7 Nucleic acids and proteins 10/28

Question 1

7.1.1 Describe the structure of DNA, including the antiparallel strands, 3’-5’ linkages and hydrogen bonding between purines and pyrimidines.

Answer 1

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Question 2

7.1.2 Outline the structure of nucleosomes.

Answer 2

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Question 3

7.1.3 State that __________ help supercoil chromosomes and help to regulate transcription.

Answer 3

nucleosomes help supercoil chromosomes and help to regulate transcription.

Question 4

7.1.4 Distinguish between unique or single-copy genes and highly repetitive sequences in nuclear DNA.

Answer 4

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Question 5

7.1.5 State that eukaryotic genes can contain ____ and _____.

Answer 5

eukaryotic genes can contain exons and introns.

Question 6

7.2.1 State that DNA replication occurs in a 5’ to 3’ direction.

Answer 6

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Question 7

7.2.2 Explain the process of DNA replication in prokaryotes, including the role of enzymes (helicase, DNA polymerase, RNA primase and DNA ligase), Okazaki fragments and deoxynucleoside triphosphates.

Answer 7

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Question 8

7.2.3 State that DNA replication is initiated at _____ point(s) in eukaryotic chromosomes.

Answer 8

DNA replication is initiated at many points in eukaryotic chromosomes.

Question 9

7.3.1 State that transcription is carried out in a _’ to _’ direction.

Answer 9

transcription is carried out in a 5’ to 3’ direction.

Question 10

7.3.2 Distinguish between sense and antisense strands of DNA.

Answer 10

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Question 11

7.3.3 Explain the process of transciption in prokaryotes, including the role of the promoter region, RNA polymerase, nulceoside triphosphates and the terminator.

Answer 11

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Question 12

7.3.4 Sate that eukaryotic RNA needs the removal of _____ to form mature mRNA.

Answer 12

eukaryotic RNA needs the removal of introns to form mature mRNA

Question 13

7.4.1 Explain that each tRNA molecule is recognized by a tRNA, using ATP for energy.

Answer 13

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Question 14

7.4.2 Outline the structure of ribosomes, including protein and RNA composition, large and small subunits, three tRNA binding sites and mRNA binding sites.

Answer 14

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Question 15

7.4.3 State that translation consists of ______, _____, _______ and _______.

Answer 15

translation consists of initiation, elongation, translocation and termination.

Question 16

7.4.4 Sate that translation occurs in a _’ to _’ direction.

Answer 16

translation occurs in a 5’ to 3’ direction.

Question 17

7.4.5 Draw and label the structure of a peptide bond between two amino acids.

Answer 17

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Question 18

7.4.6 Explain the process of translation, including ribosomes, polysomes, start codons and stop codons.

Answer 18

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Question 19

7.4.7 State that free ribosomes synthesize proteins primarily ______ the cell, and that bound ribosomes synthesize proteins for _____ or for ________.

Answer 19

free ribosomes synthesize proteins primarily within the cell, and that bound ribosomes synthesize proteins for secretion or for lysosomes.

Question 20

7.5.1 Explain the four levels of protein structure, indicating the significance of each level.

Answer 20

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Question 21

7.5.2 Outline the difference between fibrous and globular proteins, with reference to two examples of each protein type.

Answer 21

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Question 22

7.5.3 Explain the significance of polar and non-polar amino acids.

Answer 22

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Question 23

7.5.4 State four functions of proteins, giving a named example of each.

Answer 23

functions of proteins: 
1. enzymes (lactase)
2. hormones (insulin) 
3. defense (antigens)
4. structure (collagen) 
[5. transport (hemoglobin)]

Question 24

7.6.1 State that metabolic pathways consist of _____ and _____ of enzyme-catalysed reactions.

Answer 24

metabolic pathways consist of chains and cycles of enzyme-catalysed reactions.

Question 25

7.6.2 Describe the induced-fit model.

Answer 25

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Question 26

7.6.3 Explain that enzymes lower the activation energy of the chemical reactions they catalyse.

Answer 26

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Question 27

7.6.4 Explain the difference between competitive and non-competitive inhibition, with reference to one example of each.

Answer 27

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Question 28

7.6.5 Explain the control of metabolic pathways by end-product inhibition, including the role of allosteric sites.

Answer 28

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