SILKK ACADEMY Test (Unit 5 )

Transcription

1 Fig.. shows part of a N molecule. SILKK EMY Test (Unit 5 ) Name :... Paper: iolog y ate :... lass: Time llowed: 45Minutes Maximum Marks: 5 TKheory Section: [Total 7 Marks] guanine X W U Fig.. nucleotide (a) (i) Name U to X. Z U... W... X...[3] (ii) Name the bonds indicated by Z....[] (b) escribe three features of a polypeptide molecule that are different from those found in a N molecule....[3] [Total: 7]

2 atalase is an enzyme with a molecular structure composed of four identical sub-units. Fig.. is a diagram that shows how catalase is produced in cells. N mrn amino acid molecules polypeptide produced by organelle haem sub-unit of catalase assembly of four identical sub-units molecule of catalase Fig..

3 (a) With reference to Fig.., (i) name 3 process... molecule... structure.... sequence of bases...[4] (ii) state two ways in which the structure of catalase is similar to the structure of haemoglobin and one way in which it differs structural similarities [] structural difference...[] (iii) State why it is possible for a catalase molecule to bind to four substrate molecules at the same time....[] (b) The enzyme amylase catalyses the following reaction: starch + water maltose The progress of this reaction may be followed by measuring either the starch concentration or the maltose concentration at intervals of time. State which chemicals you would use to detect the disappearance of the substrate and the appearance of the product, in order to follow the progress of the reaction. disappearance of substrate... appearance of product......[] [Total: 0]

4 MQ SETION: [Total 8 Marks] What is the function of the enzyme RN polymerase? 4 to form a polypeptide using mrn as a template to form a strand of N using mrn as a template to form a strand of mrn using N as a template to form a strand of mrn using trn as a template The table gives the trn anticodons for four amino acids. amino acid asparagine glutamic acid proline threonine anticodon (trn) UU UU GG UGG cell makes a polypeptide with the amino acid sequence: glutamic acid asparagine threonine proline What was the sequence of bases on the strand of the N which was complimentary to the mrn from which this polypeptide was formed? TTTTTGGGG UUUUUGGGG GTT GUU 3 Which type of molecule is the end product of translation? amino acid N mrn polypeptide

5 5 4 The diagram shows part of a N molecule. Where are hydrogen bonds found? 5 n unidentified single-stranded molecule was described as having the following features. complementary base pairing along some of its length an area that can attach to a ribosome a site to which a specific amino acid attaches What is the unidentified molecule? N polymerase messenger RN RN polymerase transfer RN 6 Tuberculosis (T) is treated with a combination of antibiotics including rifampicin and streptomycin. rifampicin inhibits polymerisation of bacterial RN streptomycin binds to and inhibits bacterial ribosomes Which stages of protein synthesis are inhibited by rifampicin and streptomycin? rifampicin streptomycin transcription transcription transcription translation translation transcription translation translation

6 7 6 In the N sequence for sickle cell anaemia, adenine replaces thymine in a TT triplet, forming the triplet T. uring synthesis of the sickle cell haemoglobin molecule, the amino acid valine is incorporated instead of glutamic acid. What is the anticodon in the transfer RN molecule carrying this valine? T U GT GU 8 In transcription, what is transcribed and what is the product? transcribed product N mrn N polypeptide mrn N mrn polypeptide 3 4 MQ nswer Sheet