6. Nucleic acids and protein synthesis
A section of Biology, 9700
Listing 10 of 441 questions
Describe the role of the ribosome in translation. is a diagram of a section of mRNA showing the sequence of three of the codons. codon number: direction of polypeptide synthesis C C G U A A G A U State the base sequences of: the tRNA anticodon complementary to codon 1 the DNA sequence which coded for codon 3. The three codons in are near the start of the sequence coding for a protein. Explain the consequence of a mutation which deletes the U from codon 2.
9700_w12_qp_23
THEORY
2012
Paper 2, Variant 3
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There are many types of amino acids, but only twenty that are polymerised to make polypeptides and proteins in animals. Name the type of chemical reaction that occurs when two amino acids form a dipeptide. shows two amino acids, glycine and valine. Use the space below to make a drawing to show what happens when these two molecules join together to form a dipeptide. C H H H H H glycine N C O O C CH H H H H valine N C O O H3C CH3 Angiotensinogen is an inactive protein molecule. When blood pressure decreases, part of angiotensinogen is removed to form a short polypeptide, angiotensin that stimulates an increase in blood pressure. shows the base sequence within the gene for angiotensinogen that codes for this short polypeptide, the RNA codons and the primary structure of angiotensin. DNA base sequence CTA GCA CAA ATG TAG GTG GGG ….… RNA codons …… CGU ….…. UAC AUC CAC CCC UUC polypeptide primary structure Asp Arg Val Tyr Ile His Pro Phe Complete to show the missing DNA triplet and the RNA codons. State the full name of the type of RNA shown in . Table 3.1 shows the blood pressure in the right ventricle and in the pulmonary artery of a person who is in good health. Table 3.1 phase of cardiac cycle blood pressure / kPa right ventricle pulmonary artery Ventricular systole 3.33 3.33 Ventricular diastole 0.67 1.33 Use the information in Table 3.1 to explain why the blood pressure in the pulmonary artery is the same as the pressure in the right ventricle during systole, but higher during diastole. People with long-term chronic obstructive pulmonary disease (COPD) usually have blood which is poorly oxygenated during its passage through the lungs. This leads to a constriction of blood vessels in the lungs. Suggest the likely effect of this on the heart. Describe the signs and symptoms of COPD that help doctors make an early diagnosis of this condition.
9700_w14_qp_21
THEORY
2014
Paper 2, Variant 1
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Questions Discovered
441