Biology B3

Chloe Winn
Flashcards by Chloe Winn, updated more than 1 year ago
Chloe Winn
Created by Chloe Winn almost 6 years ago


Flashcards on Biology B3, created by Chloe Winn on 10/18/2014.

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Question Answer
Animal Cells They have a nucleus which contains DNA in the form of chromosomes. They also have a cell membrane which holds the cell together and controls what enters and leaves. The cytoplasm it where chemical reactions happen. In addition it contains ribosomes where proteins are synthesized it also contains mitochondria where reactions involved in respiration take place this provide energy for cell processes so liver cells and muscle cells have a lot of mitochondria because they need a lot of energy.
Plant Cells These usually have all the structures that animal cells have plus a few extra. Chloroplasts where photosynthesis happens. A cell wall made up of cellulose which supports the cell and a vacuole which is a relatively large structure that contains cell sap, a weak solution of sugar and salts.
Bacteria Cells These are smaller and simpler than animal and plant cells. The contain cytoplasm, a cell wall and a cell membrane. Bacteria don't have chloroplasts or mitochondria. They also don't have a 'true' nucleus but instead have a single circular strand of DNA that floats freely in the cytoplasm.
Respiration & Respiratory Quotient Respiration happens in every cell in the body, it is the process of releasing energy from glucose. However, this energy cannot be used directly by cells so it made into ATP which acts as the energy source for many cell processes. and transports energy to where it is needed in the cell. The RQ can tell you whether someone is respiring aerobically or aerobically. The RQ is usually between 0.7 - 1, this is aerobic respiration. If the value is greater than 1 the person is short of oxygen and respiring anaerobically. RQ = Amount of CO2 produced / Amount of O2 used.
Aerobic Respiration This is the most efficient way to release energy from glucose (using oxygen). This is the most common type. As respiration rate increases so will oxygen consumption and CO2 production. This means that the oxygen consumption can be used to calculate the estimate metabolic rate (the amount of energy being used).
Anerobic Respiration This happens when there is lack of oxygen in the body so oxygen cannot be carried around the muscles even as heart and breathing rate increases. This is not a good way to convert glucose to energy because it releases less energy per glucose molecule. The glucose here is only partially broken down and lactic acid is also produced which builds up in muscles, making them fatigued and painful. The advantage is that you keep your muscles working however, after this you cannot exercise due to oxygen debt (you nee extra oxygen (to break up the lactic acid, after this you can aerobically respire again)). You will have to breathe hard after stopping to get extra oxygen, and because the lactic acid has to be carried to the liver to be broken down , so heart rate stays high too. Glucose -> Lactic Acid (+Energy)
DNA Information Chromosomes are long molecules of coiled up DNA, they then divide up into sections called genes. DNA is a double helix, each of the two DNA strands is made up of lots of nucleotides and each nucleotides contains a small molecule called a base. DNA has four bases A,T,C and G. Each base forms cross links to a base on the other strand which keeps them tightly wounded together. The complementary base pairs are A,T and C G. Watson and Crick were the first scientists to build a model of the DNA - this was is 1953. They used data from other scientists to help build this model, this included: - X-rays, which showed that DNA is a double helix formed from two chains -Other data showing that bases occurred in pairs.
DNA Replication
Proteins Each DNA molecule contains a genetic code which determines which proteins are built and the proteins determine how all the cells in the body function.
Protein Codes in DNA DNA controls protein synthesis in a cell. A section of a DNA that codes for a particular protein is a gene. Proteins are made up of a chain of molecules called amino acids. Each different protein has it's own particular function and order of amino acids. This gives each protein a different shape, which means each protein an have a different function. It's the order of the bases in a gene that decides the order of the amino acids in a protein. Each amino acid is coded for by a sequence of three bases in the gene. the amino acids are joined together to make proteins, following the order of the bases in the gene. Each gene contains a different sequence of bases - which is what allows it to code for a unique protein.
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