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18 Cards in this Set
- Front
- Back
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Why is DNA and RNA important? |
DNA stores genetic information RNA transfers genetic information from the DNA to the ribosomes so they can produce proteins |
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What are ribosomes formed from? |
RNA and proteins |
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What is the general structure of a nucleotide? |
They have a phosphate, a pentose sugar and a nitrogenous base |
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How does the structure of DNA and RNA differ? |
The pentose sugar in DNA is deoxyribose and in RNA it is ribose DNA has A,T,C and G RNA has A,U,C and G |
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What is the difference in the overall structure of DNA and RNA? |
DNA forms a double helix with hydrogen bonds between two polynucleotide strands whereas RNA forms a single polynucleotide strand which is short in length compared to DNA |
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Why did scientists in the past believe DNA was incapable of carrying genetic code? |
It has a relatively simple chemical structure. Some thought proteins carried it which are much more chemically varied. |
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Why is DNA replication semi-conservative? |
Half of the strands in each new DNA molecule are from the original DNA molecule |
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Which enzyme breaks Hydrogen bonds between bases? |
DNA helicase |
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Which enzyme catalyses the condensation reactions that join the nucleotides of the new strand together? |
DNA polymerase |
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What is the structure of ATP? |
Nucleotide base (Adenine) A ribose sugar Three phosphate groups |
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What happens to ATP when energy is needed by a cell? What is the reaction catalysed by? |
ATP is broken down in to ADP and Pi by a hydrolysis reaction. A phosphate bond is broken and energy is released. It is catalysed by ATP hydrolase. |
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What is the Pi that is released from the break down of ATP used for and what is this process known as |
It can be added to another compound which often makes it more reactive. This is called phosphorylation. |
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When is ATP resynthesised and which enzyme catalyses it? |
During respiration and photosynthesis. Catalysed by ATP synthase. |
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Why is water important? |
It is a metabolite in lots of important reactions It is a solvent It helps with temperature control The molecules are very cohesive which helps transport in plants |
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What are inorganic ions? |
Ions which don't contains carbon. They are found in cytoplasm of cells and body fluid of organisms. |
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What are the properties and roles of iron in haemoglobin? |
It is a large protein that carries oxygen around the body. It is made of 4 polypeptide chains each with a Fe2+ in the centre. The Fe2+ binds to the oxygen. |
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What are the properties and roles of Hydrogen ions? |
pH is calculated based on the concentration of H ions. Enzyme controlled reactions are affected by pH. |
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What are the properties and roles of sodium ions? |
Sodium co-transporters helps glucose or amino acids cross cell membranes. |
