Make a to-do list everyday. Put the most important tasks on top, even if they are the least pleasant, get these over with first. Have some things you enjoy on the list, so you have something to look forward to. 2. Keep your work with you. This allows you to take advantage of wait time, on the bus, in the car, standing in line, you get the idea. 3. Don’t be afraid to say no to your friends. Its ok to say no if your friends asks you to go to a movie with them but you have a test tomorrow, if they are a real friend, they will understand. 4. Do your work when you feel the most productive. Are you not a morning person? Then don’t try to do difficult assignments before school. 5. Create a dedicated study time. Set aside some time everyday just for studying or homework. Turn off your phone during this time. Don’t check your email or the internet during this time, if you don’t need the internet to do your homework, turn off the wifi on your computer to minimize distractions. 6. Budget your time. Add up all of your time commitments for the week (practices, job, school, etc) and create a weekly schedule to follow. Before adding any other activities, check to see how much free time you actually have that week. Remember to schedule time to relax and to exercise! You don’t want to burn out. 7. Focus, focus, focus. Check your to-do list a few times a day to help keep you from getting distracted by unimportant things (like that cute kitty video on youtube!) 8. Get enough rest. A sleep deprived brain is not a highly functioning brain – you need 7-8 hours of sleep a night to be healthy. If you didn’t get everything done on your to-do list and its time for bed, just add it to tomorrow’s to-do list and get som
1. How does meiosis differ from mitosis? What is the ploidy number of the products in both processes?
2. What is non disjunction? Give an example.
3. Compare contrast asexual vs sexual reproduction. Describe pros and cons of each.
4. Describe what you learned in class on Thursday either about Molly or about chimeras.
This week in AP Bio we covered meiosis and mitosis. Both are ways for a cell to divide, the easiest way for me to remember the difference is that meiosis ends with 4 new cells and mitosis only ends with 2. Study tip (the “t” in mitosis stands for 2). We discussed how mitosis is the more efficient process because it takes much less energy to divide the cells.
Non dis junction is the failure of one or more pairs of homologous chromosomes or sister chromatids to separate normally during nuclear division, usually resulting in an abnormal distribution of chromosomes in the daughter nuclei. One example of this is down syndrome, when the chromosomes divide unevenly.
Asexual reproduction doesn’t require sex, so therefor gender isn’t really necessary. It is good because mates aren’t needed, so the organism doesn’t need to waste time or energy searching for a mate. The down side of Asexual reproduction is that there is no difference, they are all exact copies. If the mother is easily killed by a bacteria or a virus, the offspring will most likely be killed as well. Sexual reproduction is far better because it provides variation which is important to survival. With sexual reproduction there are almost no limits to the different combinations that make up the person, which can help people be immune to the same virus that killed a person living right along side them.
Learning about Molly was a pretty cool topic, it is still pretty confusing to me how exactly it worked, but here is what I know: Molly had a hereditary disease, she needed a bone marrow transplant, and the parents wanted to have another child to treat their daughter. Basically it is impossible to find a random donor who would have the same cell protein as their daughter Molly. The solution that they came up with was to have another child to help treat Molly, the issue was that they didn’t want to pass the disease to a second child. They ended up having a “test tube baby” and made sure that the disease could not be present in the new baby. The chances weren’t great, but they also weren’t impossible. They ended up successfully having a baby with the matching genes of her sister and they were able to transplant and help Molly to survive for a little bit longer.
This week in AP Bio we did a lot regarding cancer. We started out learning about Oncogenes as well as tumor suppressor genes. Oncogenes can be compared to the gas pedal of a car, because the issue with an Oncogene is that it doesn’t stop, the cell grows non stop out of control which can cause cancer. Tumor Suppressor genes can be compared to the break of a car, normally they help the cell to divide, repair damaged cells, and tell the cell when to die. When Tumor suppressor genes malfunction, the cell is allowed to keep growing, which can cause cancer.
I learned that men are more likely to get cancer due to their chromosomes. Women have two x chromosomes where as men have one x and one y. When women have a mutation on one of their x chromosomes they can fall back on the other, on the other hand, if men have a mutation occur on their x chromosome they will get cancer because it doesn’t have anything to fall back on.
What we concluded in our small groups were that most types of cancer have common pairs of genes as well as function. For example lung cancer would be almost all related to tumor suppressor gene and cell survival. Knowing the combos might help to make it preventable and maybe help with a cure.
It really surprised me that men are more likely to get cancer than women. It makes sense once you take a look at the reasoning, but I always thought women were more likely to get cancer.
It was really cool to learn about why things like sunburns and age make you more likely to get cancer. When you get a sunburn, your cells need to work really quickly and tons of cells are produced in a short amount of time, which increases the chance of an error/mutation. As you get older, you have had more cells replaced in your life than someone young which again leaves more room for error.
My question: Are the genes involved with the chromosomes linked to different types of cancer?
Well we finally got some days off due to snow THANK GOD, but that did nothing to stop the train known as AP Bio class. This week we got more into photosynthesis specifically the reactions and the two photo systems.
- The overall structure of the chloroplast looks like the diagram above, the chloroplast is responsible for photosynthesis in plant cells. Photosynthesis takes place on the Thylakoids of the chloroplast. In light dependent reactions, sunlight is absorbed by chlorophyll. In light independent reactions, the Calvin cycle occurs and carbs are assembled. Thylakoids are the flattened sacks inside the chloroplast, this is where light reactions of photosynthesis take place. The stroma is the fluid-filled space that is surrounding the grana, and is also involved in the synthesis of organic molecules from water and carbon dioxide. This stroma function is generally known as either the light independent reactions or the dark reactions. Photosystem II I will talk about first because it actually occurs first (scientist are just lazy af). I am going to refer to the photo systems as P1 and P2 (just remember reversed order). P2 is the first light-dependent reactions of photosynthesis. It is located in the thylakoid membrane of plants. By replenishing lost electrons with electrons from the splitting of water, P2 provides the electrons for all of photosynthesis to occur. P1 (second part) is responsible for providing high energy electrons to reduce NADP+ and produce NADPH to be used in the Calvin cycle. ATP synthase is pretty much a pump, it is responsible for powering our cellular processes. The electron transport chain uses the electrons from electron carriers to create a chemical gradient that can be used to power oxidative phosphorylation. In the Calvin cycle, carbon atoms are incorporated into organic molecules and used to build three-carbon sugars. This process is fueled by, and dependent on, ATP and NADPH from the light reactions. It is not light dependent though.
1. Compare and contrast Anaerobic cellular respiration and Aerobic cellular respiration. In your answer, address glycolysis, the citric acid cycle, oxidative phosphorylation, lactic acid fermentation, alcohol fermentation, NADH, FADH2 and ATP. 2. Explain why the disruption of chemiosmosis and the proton motive force can be detrimental to eukaryotic organisms. Provide a real life example. 3. Compare and contrast obligate and facultative anaerobes. 4. In the following redox reaction, identify which molecules have been oxidized and reduced. Also identify the reducing agents and the oxidizing agents. C6H12O6 + 6O2 —>6CO2 + 6H2O + Energy
It has been a while since the last blog and we are now trying a new blog where we have questions to answer as well as describe what we did.
This week we did quite a bit of work on cellular respiration as well as some work on photosynthesis. Cellular respiration and photosynthesis are pretty much the reverse of each other, we learned about that in freshman Bio. Respiration takes in oxygen and releases carbon dioxide, while photosynthesis takes in carbon dioxide and releases oxygen. Now of course it isn’t really that simple, that is just the easiest and most condensed way to remember it.
In our cells, we use cellular respiration for the main purpose of energy. Without cellular respiration, we as people would die. We have two types of cellular respiration, Aerobic and Anaerobic. Aerobic requires oxygen while Anaerobic doesn’t. Aerobic respiration is the one that I think of when it comes to cellular respiration, simply because we breathe. Without oxygen, Aerobic respiration could never occur and we would die. The bodies energy comes from cellular respiration, specifically the mitochondria, which break down glucose using oxygen. Glycolysis is the first step of cellular respiration, it occurs outside of the mitochondria in the cytoplasm of the cell. It is caused by the breakdown of glucose, it creates 2 ATP as well as pyruvate and NADH (which are used in the next step). The next step is the Krebs cycle or the citric acid cycle (really just preference) In the Krebs cycle, the 3 carbon molecule is broken down, releasing 2 co2 as the waste. 2 ATP released While this is occurring, electrons are being added to NADH and FADH for the next step. The next and final step is the electron transport chain, which pretty much takes all of the electrons from the original glucose to be used in the body. The electrons are used to pump the protons (hydrogen molecules) into the membrane space and they are added to the oxygen we breathe (aerobic respiration) as well as the other protons to make water (H2O). This step can produce 32 ATP alone. From all of the steps of Aerobic respiration combined, 36 ATP can be created. Now for Anaerobic respiration, this is normally used during exercise such as running or swimming. The problem that we run into with Aerobic respiration is that in glycolysis, the electrons used go to NAD+ turning it into NADH and the problem is that eventually, we run out of NAD+. Anaerobic respiration solves this problem, but all athletes will know the consequence. Pyruvate can change into lactate, which will accept the extra electrons and allow the cycle to continue. The issue with Lactic acid fermentation is that the acid begins to wear on your muscles, it makes you sore and breathe more heavily. This is because the lactic acid needs to be broken down as carbon dioxide and released when you exhale.
2. Chemiosmosis is the movement of ions across a semipermeable membrane, down their electrochemical gradient. Why this is important to us is because in cellular respiration, hydrogen ions need to be able to move across the membrane in order to generate ATP. If there was an issue with this is that if it were to have an issue, the body would stop getting the majority of it’s ATP and die. A real life example could be a disease that doesn’t allow chemiosmosis to occur, and the patient would die unless it was fixed.
3. A facultative anerobe is an organism that makes ATP by aerobic respiration if oxygen is present, and can switch to fermentation or anaerobic respiration if there isn’t oxygen. An obligate anaerobe can’t make ATP in the with oxygen, and die in the presence of oxygen.
4. Oxidation and reduction both have to do with electrons, one is gaining while the other is losing. The Best way to remember this is OIL RIG (Oxidation is losing, Reduction is gaining) In cellular respiration, NAD is being reduced, making it the oxidizing agent. NADH is being oxidized, making it the reducing agent.
Wow that was probably the longest blog that I have ever written and it actually helped me to get a better understanding of Cellular respiration, so although it wasted over an hour of my time, it was beneficial in the long run.
This week in AP Bio we began working on signaling. We started off with bacteria (may have been last week, I forget), then how insulin effects diabetes, and we finished off with cellular respiration.
To learn about bacteria signaling we watched a Ted video which was interesting, but it was also pretty scary to learn about. We learned about how some organisms use signaling to their advantage such as the Hawaiian bobtail squid. The Squid uses the signaling in Vibrio Ficheri (a bacteria) to mirror the exact amount of light the moon shines through the water, this way the animal casts no shadow which helps it not only to hunt, but avoid being hunted. For years in the summer, I have gone to the dock late at night and jumped in with friends or threw rocks in just to see the green glow of the bioluminescence. What the lady in the Ted video explained is that if you had only one bacteria cell or even just a few, you would see no glow. It is when they are all together they are able to communicate to each other, which is what creates the beautiful glow. All bacteria known to man communicate in the same way; they can send signals out, and they can receive them. Most of the time, the signal will just float away, nothing will happen with it. But in a group, there are a ton of signals floating around as well as more receptors so the signaling is much more effective.
The communication is really cool to see visually, and is even a survival mechanism for some animals. Bacteria are good because they keep us alive, they digest food and they give us a protective barrier. Why they are bad is because of quorum sensing. Quorum sensing is basically a vote for bacteria, it allows them to count and to plan a synchronized attack on the host. For a large host such as a human, if bacteria were to attack with few numbers or not all at once, our immune system would wipe them out. On the other hand, if the bacteria attack all at once, they may be able to quickly kill the host before they recover. (this is why you can get sick over night). What makes the bacteria even worse is what was recently discovered. Bacteria have a universal language and can talk to other bacteria which is very bad news for both the host, and for medical treatment.
This week in AP bio we began learning about cells. Although we learned a bit about cells in regular Bio, I forgot nearly all of it so it pretty much felt like we were going over new material.
There are two main types of cells, there are Eukaryotic cells and Prokaryotic. Eukaryotic cells are found in plants and animals, while Prokaryotic are found in bacteria. The Eukaryotic cells found in plants and animals are very similar, but they do have some differences. Plant cells contain a few extra things: The cell wall, Chloroplasts, a central Vacuole, and the Nucleolus. The cell wall is found only in plant cells, but both plant and animal cells have a cell membrane for protection. Chloroplasts are only found in plant cells(Chloroplasts take in sunlight and create ATP and carbs for the cell). Although animal cells don’t contain Chloroplasts, they do contain Mitochondria which are very similar, only they make energy through cellular respiration. The central vacuole is only found in plant cells, but there are vacuoles in animal cells too, only they are much smaller. The nucleolus is found only in plant cells, both plant and animal cells contain a nucleus, the nucleolus sits inside of the nucleus. The main difference is that the Nucleolus is more about creating Ribosomes than storing DNA.
Prokaryotic cells are much more simple then Eukaryotic cells are. The main difference between the two (other than shape) is that Prokaryotic cells don’t contain a real nucleus. The Nucleoid is similar to a Nucleus in the way that they are both responsible for the main storage of DNA in the cell. The main difference is that the Nucleoid is not membrane bound like the Nucleus is, so it is a less structured way of storage.
This week in AP Bio, we had a short week and began to cover enzymes. Enzymes are proteins, which are made up of amino acids. They are used to catalyze chemical reactions. We learned that they are good because they can lower the activation energy of a reaction which basically makes it easier and can speed up the process. Enzymes are NOT consumed in the reaction, they are just there to speed up the reaction.
Enzymes have what is called an active site (pretty much a hole in the enzyme), which is filled by what is called the substrate. The substrate fits perfectly, the video referred to it as lock and key (although Mr. Dunn didn’t like that metaphor). When the substrate is inside of the active sight there is a “chemical tug” which lowers the activation energy and can break it into products. Enzymes can be both turned on, and turned off. There are two ways to turn an enzyme on, you can just not produce them until they are needed, or you can activate them. To activate them, you add something to the enzyme to make it do what it needs to do. There are Cofactors and Coenzymes. Cofactors are small inorganic chemicals that contain no carbon. Cofactors are organic and they do contain carbon. To turn enzymes off, we can use inhibition. There are two types of inhibition, the first one is called competitive inhibition, which is when you use an inhibitor (a chemical of some sort) to block the active site and deny any substrate from getting in. The second type of inhibition is Allosteric inhibition (or non competitive inhibition). Allosteric inhibition is when the inhibitor bonds to what is called the allosteric site which then covers up the active site. This makes it impossible for the substrate to get in. Another type of Allosteric inhibition is when the inhibitor goes to the allosteric site but doesn’t block it, instead it changes the shape of the active site. If the active site doesn’t perfectly fit the substrate, it won’t go in.
To represent this in class and try to gain a better understanding, we did a lab involving toothpicks. The idea being that there are 100 tooth picks in a bowl, without looking, you are meant to reach in and break as many toothpicks as you can. The catch being that you can’t break a toothpick that is already broken, and you never replenish the number of toothpicks. Theoretically the rate of toothpicks being broken should get slower and slower because there are less whole toothpicks to break. We did the lab a second time, but this time we were supposed to change something about the experiment. Our group chose to have me break the toothpicks with only my left hand instead of both hands. The experiment should have worked on paper, the issue with our experiment was the human error. At first I was very slow at breaking the toothpicks, but later on I was breaking them much faster even though there were less and less toothpicks available to break. I guess I adapted, too bad this wasn’t for the evolution unit. While our graph should have increased less and less gradually, I instead got a graph that went up and up and up.
What we wanted. What we got.
Well…. At least we tried
This week in AP Bio, we began to learn about acids, bases, and buffers and how they play a role in pH. We began using pH in first year bio as well as a bit in chemistry, but we never went much into how it actually works.
The easiest way for me to understand pH is with a mental picture of a scale. pH goes from 0-14, the higher the number is; the more basic the substance is, the lower the number is; the more acidic the substance is. Water has a pH of around 7 making it perfectly nuetral, it is not really considered acidic or basic. As long as it is understood that 7 is the center pH, it is pretty easy to understand that anything below 7 would be considered and acid, while anything above 7 would be considered a base.
pH is commonly known as “the concentration of hydrogen.” Acids have more hydrogen’s than bases do, so when dissolved in water it will give away the H+ also known as the hydrogen ion. Bases do the opposite, when dissolved in water they will donate the hydroxide ion, also known as OH- .
We learned about how pH can affect athletes by looking at the pH of blood. Blood in the human body has an average pH of approximately 7.35, which is very slightly basic. When you exercise, your body creates acid known as lactic acid. The acid of course being an acid lowers the pH of your blood. In order to get the pH back to normal, you start to breathe more rapidly in order to release Co2. While most people belive it is to increase the amount of oxygen in your body, that isn’t the primary reason for the heavy breathing. The release of Co2 helps to raise the pH of your blood and get rid of the acidity. If the pH of your blood drops below 7, you can go into a coma or even die. So it is crucial not to let the pH of your blood get to acidic or too basic. We discussed how in theory it would help an athlete to hyperventilate before a game or a run or whatever it may be. Because of the release of Co2, you could make your blood more basic before you start the exercise, that way the acid would just be bringing the pH back to normal before it started to lower it further.
I am still confused on some aspects of how this all works, but this week has definitely helped me to get a base line idea of pH and what acids and bases really mean. I am sure that we will go more in depth into pH as the year goes on and I may be able to give a better synopsis of what is going on.
This week in AP Bio, we did a reading for homework and took notes on either Metabolism First or Replication first hypothesis for evolution on earth. After the reading, we came into class and received a paper that basically said that what we were arguing was wrong and why the other was right. During a debate that was really more of a class wide discussion, we argued for one or the other using points from the documents to back us up.
Main idea (Replication first): Replication first, also known as the RNA World Hypothesis states that long ago, RNA was created from ribonucleotides that were accumulated on earth. RNA could accurately copy itself over and over. The more RNA that was created, the more errors would occur, causing each offspring to be slightly different. Life was able to evolve because ribonucleotides attached to specific amino acids making proteins. Science has proved that this theory makes sense because we can create sugars and these nucleotides using the gasses and the conditions on earth, using the simple building blocks. We can skip the creation of building blocks and go straight to creating the nuleotides (which are linked to RNA). Clay Montmorillonite (which is only found on earth) can serve as a catalyst, it holds nucleotides and RNA. RNA replication was argued to be improbable because of how long it would take and how unstable they would be, but this had plenty of time, millions of years even to create stable and evolved life forms.
Main idea (Metabolism first): Also known as the Iron-Sulfur world Hypothesis, claims that mineral catylists in deep sea hydro-thermal vents could promote evolution. These sites produce Hydrogen Sulfide (H2S), it can react with iron sulfide minerals and catalyze a series of chemical reactions creating a reverse Kreb Cycle. The Kreb Cycle is a series fo chemical reactions that take place in all aerobic cells today, it extracts energy out of organic molecules taking in CO or CO2 and reduces it using electrons to form complex organic molecules. The end products from these reactions become the start for the next one, it is a self sustaining process so it can happen constantly. The organic molecules formed will accumulate and some will form membranes, the membranes can protect the catalyst and separate it from the rest of the ocean and form a cell. Because this is self sustaining, it could happen many times explaining cell structure.
At this point in time, it is hard for me to argue towards one or the other because I am not very educated as far as how this truly works. If I had to choose, I would choose the RNA world hypothesis because RNA replicating itself with error occurring over millions of years makes more sense to me than underwater vents creating a self sustaining cycle of cell creation that turned into organisms. To have better and more valid arguments, I would need to read more into these topics.
This week in AP-Bio, we continued to practice using the Hardy-Weinberg equations and we continued to work with cladograms. I am not really sure how much new stuff we covered this week, it seemed like it was all stuff that we started last week, only more in depth.
We covered how to properly make cladograms, which so far has been pretty straight forward, but will most likely get very difficult down the road. The first thing that I do when making a cladogram is find the two organisms that are the least related genetically. If you find the two that are least related, you can start the cladogram with one of those organisms (the least evolved or least complicated should be at the bottom) and the other should be at the top (the most evolved, often most traits acquired). From there, I would work bottom up. Find the organism most related to the one at the bottom, the one that is most related genetically will be the next organism on the graph. This continues until it reaches the top. If this is done properly, you should be able to write the traits below as they are acquired, and most of the time, that trait will continue through the rest of the organisms on the cladogram.
At first, it was hard for me to understand how this all worked. When I was watching the video for the Bio homework last week, they mentioned how you can rotate parts of the tree at each common ancestor and it will still give the same results. My issue with understanding how that works is that I thought how close the organisms were to each other at the top showed how related they are, but that is not exactly true. When comparing organisms the first place to look should not be at the organism itself, but at the most common shared ancestors of the organisms. For example if you look at the cladogram above, you will see that the organisms are ordered: Sharks, ray finned fish, amphibians, primates, rodents and rabbits, crocodiles, birds. Based on the fact that you can rotate the tree at ancestors, you could rotate it so that birds were the organism closest to amphibians, so it may not always be primates in that spot.
In class we covered a common mistake made by students. The idea of drift got passed around as “the chance of genes being passed on.” Many students (including myself) were under the impression that drift was like a human stepping on a group of green bugs, and because of that, only the brown bugs would pass along their genes. We concluded therefore that drift was completely random, but that’s not really true.
We covered a topic in class that was made interesting thanks to the silver fox. We covered selective breeding, we learned about it through a screwed up Russian guy named Belyaev. He was a man who wanted to pretty much take the sport out of hunting and make it easy slaughter instead. What was happening at this time was people would kill the foxes and sell the fur (which is pretty cool fur not going to lie), but this man was tired of the foxes biting and attacking the people who were hunting them. So instead of making bite proof pads or something, he decided to just breed the fight out of them. To do this he took the nicest/most curious foxes and bred those together while just killing the mean ones. We found that this did work, the breeds later on were way nicer then the original ones, but something that was not predicted happened. The foxes began to develop new traits such as shorter tails, floppy ears, and change in color pattern. What Belyaev found was that the trait for niceness, was linked to many other traits as well, by altering one trait, he altered many. This gives us an idea of why dogs came to look so different from wolves, and why there is such a huge variety, it’s because when you breed for one trait, you often alter many.