Biology

I am struggling with this unit.. i dont no wher to start my revision, i dont have a clue! im also repeating module 1 because i was 3 marks off an A.. and i want to do dentistry so I need top marks!! Can someone please give me notes or something, cause all i have as notes is the revision guide and a huge textbook :( and my exams are in three weeks!!

A researcher is given the task of designing a protein that will bind to a receptor very well. The receptor's binding site has strong positive charges at the edges and negative charges in the center. How would you go about designing the protein to bind to it?

Which organelle modifies cell products, packages them for distribution, and then may turn into vesicles and bubble off the surface of the cell?

(This is for AS environmental studies) could I have reasons for how these factors are important for life on Earth. Thanks.

-distance from sun -tilted axis -mass of the planet -magnetic field -day length

A-level bio Q. How does ions cross the phospholipid bilayer? can very small ions just diffuse across?

Define photosynthesis

describe the path that water takes as it enters and exits a maple tree

I'm doing past exam questions and quite a lot of old exam questions ask about the effect of cyanide on respiration - is this on the new AQA specification??

how are we supposed to study for the biology paper unit 3, report questions

Animal cells, including those of humans, are eukaryotic cells. Explain the link between mitochondria in muscle cells and rough endoplasmic reticulum in enzyme secreting cells from salivary glands. The cells in tadpole tails are specialised and contain many more lysosomes compared to its other cells. Describe he production of lysosomes and suggest how this adaptation allows a tadople's tail to be absorbed as it changes into a frog. Animals tend to be multicellular organisms. Give the levels of organisation responsible for creating organisms.

Plssss anyone hellllppp

I would like some help with the revision

How do you find out the true value of a set of results in Biolgy

what would the gradient show?

Really need help asap

I need help on this for my ISA..so please any accurate information will be beneficial and can I have the website or books for where you received your knowledge from. Including authors and links. Thank You .:)

how to separate water from flour

How would rinsing your mouth with salt reduce the swelling of gums?

Any tips for IGCSE Biology that may help me?

In chickens, males have two Z sex chromosomes (ZZ) and females have one Z and one W sex chromosome (

discuss the leaf modifications of poison ivy and squash plants that are designed to prevent organisms from touching or eating their leaves

Why do phospholipids form bi-layers and triglycerides form droplets??

1. The genes for ruby eyes (rb), tan body (t) and cut wings (ct) are all found on the X-chromosome of Drosophila melanogaster. All of these are recessive traits. They map in the order rb, ct, t with 12.5 map units between rb and ct and 7.5 map units between ct and t. Suppose you cross a cut wing male with a homozygous female that is both tan and has ruby eyes.
2. What will the F1 females look like?
3. Draw map of the section of the X chromosomes that has these 3 genes for the F1 females
4. Assume you testcross your F1 females.
5. What progeny classes would you expect? ii. Give approximate numbers for each class based on a total of 2000 progeny.
6. Assuming the i=1 and there are no double crossovers.
7. Assuming the i=0 and there are the expected number of double crossovers.

Could I have info about how endangered the Mexican Walking Fish is please :)

What is the main limitation of light microscope compared with electron microscope?

Need , tips, practical help in improving my grade ... any tutors willing to help please..

What is the definition of osmosis

What are the raw materials for photosynthesis?

Phytoplankton are microscopic autotrophs that are the foundation of many aquatic food chains. The amount of photosynthesis carried out annually by ocean phytoplankton alone is of a similar magnitude to that of all terrestrial plants combined, making them an important subject for ecological research. Ocean phytoplankton photosynthesis can be studied using a wide range of techniques, from satellite imaging to measure whole oceans to collecting small samples and analysing their behaviour in the laboratory.

(a)In recent years phytoplankton have been investigated as a potential source of energy for humans. Researchers have therefore been interested in whether these organisms could be ‘farmed’ to provide food or fuel. In terms of biomass, Gross Primary Production (GPP) in phytoplankton living in a layer just below the surface of a typical ocean area is 4102 g m−2 yr−1 If you . assume the energy value of phytoplankton is 6 kJ g−1, calculate the GPP in terms of kJ m−2 yr−1 .Show your working clearly .

(b) If a human needs to eat about 10 000 kJ per day, estimate (to the nearest gram) the mass of phytoplankton that would be required to meet their daily energy requirements. Based on this value, approximately what proportion of her own body weight in phytoplankton would a 60 kg woman need to eat over the course of a year, if this were her only source of energy? Show your working clearly.

(c) Farming phytoplankton to harness solar energy for human food or fuel would presumably require cultivating large numbers of these organisms in a carefully designed artificial environment. Suggest two features that could be incorporated into the design of a phytoplankton ‘farm’ to optimise the Net Primary Production (NPP). Briefly describe why each design feature would be useful. (One sentence for each)

What are some issues people can face of they have too much protein in their diet?

It comprises of phosolipids right? The phosphorus is hydrophilic, and the fatty acids hydrophobic. I asked my teacher how the water diffused in and out of the membrane then, and she said. "The water molecules are small enough that they just go through"

Now. I know I'm the student, but that doesn't fit with me? Then I learnt about the transport protiens. And that made more sense.

But, is that the defenite way, and if so, what really happens in the process of water going in and out of the membrane?

What are the endoskeleton and evoskeleton?

What happens in the Calvin cycle?

What is an allele?

What is respiration?

During meiosis :)

when the 2nd tRNA is formed between 2 amino acids what bond is this called?

which type of blood vessel in the circulatory system has a pulse?

Why are most rodents eyes completely black?

why is asceptic technique important in microbiology

why is respiration an important process in the cells of germinating seeds

Is it ok to write the answer in bullet point form or does it have to be in a proper essay format?

Why do muscle cells have a high amount of mitochondria?

I approach this by thinking of a cell as my entire body. If I lie in bed and do nothing all day I am like a fat cell. I only need a little energy which I get from a small amount of food in the way that fat cells only a little energy which they get from a small number of mitochondria. On active days I am like a muscle cell. I need lots of food in the way that fat cells need a lot of mitochondria to give them energy. Mitochondria are the energy factories for all cells. ATP synthesis occurs in them by ADP and Pyruvate synthesizing to create ATP, which is energy. Muscle cells work hard to move and contract and this is why they require a lot of energy thus they contain more mitochondria to produce a high level of ATP

Why do heart cells have a high amount of mitochondria?

Mitochondria are the organelles in the cell that produce energy in the form of ATP. When cells complete the process of cellular respiration they produce oxygen, glucose (C6H12O6), and this form of energy. The heart muscle is truly amazing in that it is constantly contracting and relaxing, and never tires. Mitochondria are the means of providing energy for this constant activity, and a lot are needed for this. As the heart is constantly pumping blood around the body, it needs a rich supply of oxygen and glucose. There are more mitochondria found in heart cells because this means we are able to produce enough energy to keep it functioning efficiently. This is a trait we humans have evolved in order to increase our chances of survival.

Which process generates the most ATP per glucose molecule metabolized?

Aerobic respiration in the mitochondria generates the most ATP per glucose module. Aerobic respiration in the mitochondria, more specifically the Keen cycle. In the glycolysis stage, for each molecule of glucose, 2ATP, 2NADPH and 2 pyruvates are made. Pyruvate from glycolysis enters the kreb cycle where a net of 36ATP molecules are made along with more reduced NADP and FAD. That’s a lot of ATPs pet glucose. Remember this value is the theoretical maximum. As this is an enzyme controlled processes, the actual number of ATP produced maybe a lot lower

Q - How does tissue fluid return to the circulatory system?

In my textbook, it says the main reason is that it re-enters the capillaries by the loss of hydrostatic pressure within them, so by the time the blood gets to the venous end of the capillary the hydrostatic pressure is less within the capillary than outside them in the tissue fluid, so the tissue fluid is forced back into the blood in the capillary. However, when I look at mark schemes it says that it mainly re-enters by osmosis? How does it move in by osmosis? (I know that the remaining moves back into the bloodstream via the lymphatic system)

Answer

As the blood moves through the capillary it is getting further from the heart and pressure is being split between branches. This means hydrostatic pressure, and the force that attempts to push the fluid through the walls, decreases, However, osmotic pressure (basically how big the gradient of water potentials is) must get higher than hydrostatic pressure to ‘over power’ it. With nutrients moving out with the water, this means water potential would hardly be affected. However, there are special proteins in the plasma of the blood called plasma proteins. Being soluble (unlike may proteins) they alter water potential and being large (like many proteins) they are unable to cross the semi-permeable cell membranes of the capillary wall. As water moves out, the concentration of these proteins increases, and the water potential in the capillaries decreases. The gradient of water potential from outside to inside gets higher, as does the osmotic pressure. Eventually, osmotic pressure is higher than hydrostatic pressure, and fluid is forced back in! Any excess is returned via the lymphatic system, entering dead-ended lymphatic capillaries. This system of vessels eventually drains the excess fluid back into the circulatory system.

We all know that a well designed and rigorous revision schedule is necessary to pass any exam. Make sure to use plenty of past papers and understand the types of questions that are likely to come up. This will put you at ease and reassure you that you can answer the exam. Once you're in the exam however, there are plenty of tips we can offer you to help improve and optimise your answers and exam performance. During the exam:

1. Read through the exam! Prioritise the questions that you know the answers to easily and focus on getting those answers down. This will put you at ease. Then move on to focus on the more difficult questions, paying attention to how many marks each is worth.
2. Manage your time. Use the number of marks per question to allocate your time. If you have a 1-hour exam and 60 marks, then spend no more than about a minute per mark. Specifically for AQA, they tend to put simpler questions at the start of a paper and harder questions at the end.
3. Answer the question. Read through the question carefully and make sure you know what it is actually asking for.
4. Be clear and concise. Make sure to put down only relevant information. Don't hesitate to plan your answer if it needs to be a bit longer. Make sure your sentences are short and precise and clearly answer the question. If you are asked to show your working, do so clearly, making use of the available space to answer the question.
5. Cross out mistakes. Don't lose silly marks by leaving incorrect information on the page. Make sure it's cleary crossed out.
6. Stay relaxed! If you're getting annoyed, pause and collect yourself and move on to a question you can answer.
7. Re-read your work. If you have time, make sure to re-read what you've done.
8. Keywords. Especially in biology you are going to be using a number of unfamiliar words. It is a good idea to know how to spell them and which subjects they relate to.

what are vertebrate groups?

Oxygen is one of the basic needs for life but ever wondered what is the role of oxygen in our body? Why it is so important to intake oxygen? That is why we dedicated this specific resource to teach you how plants utilize oxygen and what happens if they don't have oxygen?

What is Aerobic Respiration?

Let's start with the easiest ones. The term "Aerobic Respiration" refers to a set of reactions that takes place because of oxygen. Thanks to oxygen, the chemical energy will be converted to ATP (Adenosine triphosphate). The purpose of ATP is to carry the energy in a cell. In some books, it is also called an energy currency for a cell. Without ATP, a cell will die and that is why plants do aerobic respiration to make sure that their cells are full of energy for other purposes. All living things carry out aerobic respiration in order to live. We will talk about it in detail in the upcoming section how it converts chemical energy into ATP.

What is Anaerobic Respiration?

It is the opposite of aerobic respiration. The word, "Anaerobic" means without oxygen. In simple words, a series of metabolic reactions occur without the utilization of oxygen. Does that mean the cell will not generate any kind of energy? No, it will still provide energy but in a very less quantity. Plants do undergo anaerobic respiration too. Honestly, there are not so many reactions in anaerobic respiration but they do provide very quick energy to the cell in large amounts. Plants and microorganisms are the best examples of anaerobic respiration. Many microorganisms contain sulfate in the transport chain (at their end) however, some of them uses nitrate .

Process of Aerobic and Anaerobic Respiration

The process of both respiration starts when chloroplast makes glucose using solar energy. This process is known as photosynthesis. The glucose molecule contains 6 carbons, 12 hydrogens, and 6 oxygen atoms. The chemical formula of glucose is . Glucose is food for plants. This molecule undergoes a series of reactions that will convert glucose into 38 ATPs. Although, approximately, 40 ATPs are produced the respiration process consumes 2 ATP of its own and that is why 38 ATPs are formed. Glucose undergoes a reaction called "Glycolysis" that converts glucose molecules into pyruvic acid. One molecule of glucose produces 2 molecules of pyruvic acid. This is the first phase of both, aerobic and anaerobic respiration. This reaction also releases two more things, 2 ATP as well as . Let's keep track of ATPs and because they are very important, glycolysis produces pyruvic acid with 2 ATPs and . From this phase, aerobic respiration separates from anaerobic respiration. Do note that the process of glycolysis consumes 2 ATP.

For Aerobic Respiration

For Aerobic respiration, there are two conditions, and both need to be fulfilled. If one of them doesn't fulfil then there will be no aerobic respiration. The first condition is pretty simple, there should be oxygen for aerobic respiration. The second condition is the requirement of mitochondria. The above picture shows mitochondria. Once the pyruvic acid enters perimitochondrial space (intermembrane space), it converts to acetyl coenzyme A (Acetyl Co-A). This reaction only occurs in this region because the enzyme that converts pyruvic acid to Acetyl Co-A is available in this space only. This reaction will release 2 more . Till now, we have 2 ATPs and . Now Acetyl Co-A will be transferred to the matrix of mitochondria where the most important reaction occurs which is known as the Krebs cycle. The Krebs cycle will release and 2 GTP (Guanosine-5'-triphosphate). GTP plays a very important role in the synthesis of RNA during the transcription process. It is used as an energy source that binds the amino-bound tRNA to the A site of the ribosome. Since it is also an energy source, we can say that GTP is equal to ATP for this case, which means Krebs cycle produced and 2 ATP. This is the second phase of aerobic respiration. After the Kreb cycle, we are left with 4 ATPs and , and , the question is this process releases 38 ATPs, where are the remaining 34 ATPs? The answer is with the help of the cristae. The next step is to convert and to ATPs and that is where the role of cristae starts. The process of converting and to ATPs is called Electron Transport System (ETS). Through this process, produces 3 ATPs, and produces 2 ATPs. The whole process released and , let's calculate how much they are equivalent to ATPs. means 30 ATPs and means 4 ATPs, all-together we have 34 ATPs. Let's calculate the total amount of ATPs produced in aerobic respiration. 2 ATPs were formed during the glycolysis, 2 ATPs were formed because of the Kreb cycle, and 34 ATPs were formed by converting and to ATPs in the cristae. If we sum up all the ATPs, we will get 38 ATPs and that is how aerobic respiration occurs.

For Anaerobic Respiration

After the glycolysis reaction, we got pyruvic acid. Since there is an absence of either mitochondria or oxygen or even both, the products will be different and different amounts of ATPs will be produced. The pyruvic acid will turn into ethanol and carbon dioxide by utilizing the . In the case of an animal cell, it will produce lactic acid. The glycolysis decomposes into pyruvic acid and doesn't require oxygen. It is already a part of anaerobic, therefore, the first phase will occur without any trouble. Let's count the ATPs produced in this respiration. Glycolysis produces 2 ATPs, and conversion of pyruvic acid to ethanol and carbon dioxide doesn't release any ATP, therefore, we are left we only 2 ATPs. In short, anaerobic respiration produces only 2 ATPs. If both, mitochondria and oxygen are present, then aerobic respiration will be preferred, however, in the absence of any of either of them will prefer anaerobic respiration.

What is the word equation for aerobic/anaerobic respiration?

Both processes have the same reactants but different products because of different conditions. In aerobic respiration, glucose will be broken into carbon dioxide and water.

This is the overall equation of cellular respiration. This means that after reaction in cytoplast, mitochondria, and ETS, these are the products. After balancing the equation, it shows that six moles of glucose react with six moles of oxygen to release six moles of carbon dioxide and six moles of water with thirty-eight ATP. Below is the equation of anaerobic respiration.

This might look simple but it isn't. Aerobic respiration goes through a series of metabolic reactions that should be talked about in detail. Each step in the aerobic reaction contains a lot of reactions that will be too much for this resource, let's just keep it simple for this one.

Difference Between Aerobic and Anaerobic Respiration

Reaction with oxygen and without oxygen isn't the only difference in both respiration processes, they are a few more differences. Below is the table that shows the differences.

Conclusion

The above process description is just a summary of aerobic and aerobic respiration. Aerobic and anaerobic respiration are very complex respiration processes. As a matter of fact, there is a huge process flow diagram of both of them with their intermediates that requires a lot of time to understand. Aerobic respiration is very common and found in many living things, however, anaerobic respiration is done on an industrial level for manufacturing ethanol and lactic acid. This domain is called biochemical engineering and let's talk about it next time.