summary

Question 1

general chemical formula for monosaccharides

Answer 1

CnH2nOn or (CH2O)n

Question 2

cyclisation of monosaccharide

Answer 2

carbonyl gap picks up H, Oh group loses H and linked by O. arranged from Fischer projection (when monosaccharide) to Hayworth projection when cyclised

Question 3

ester bond

Answer 3

between fatty acids

Question 4

phosphodiester bond

Answer 4

in DNA between sugar and phosphate. phosphate linked to 3’ carbon atom on one sugar and 5’ carbon on another

Question 5

alpha structure

Answer 5

when hydroxy grp on anomeric carbon on opposite side to highest number carbon (furthest away from it)

Question 6

beta structure

Answer 6

when hydroxy grp on anomeric carbon on same side to highest number carbon (furthest away from it)

Question 7

alpha linkage between monosaccharides

Answer 7

If both on same side

Question 8

beta linkage between monosaccharides

Answer 8

if both on opposite sides

Question 9

glycosidic bond

Answer 9

between 2 monosaccharides to make carbohydrate

Question 10

starch is an eg of a

Answer 10

polysaccharide

Question 11

glucose and fructose are

Answer 11

monosaccharides

Question 12

most common site of phosphorylation of nucleotides found in hydroxyl gap attached to the

Answer 12

carbon 5’

Question 13

numbering nucleotides

Answer 13

pyramidine (1ring)- sugar attached to N1 of base.
purine (2 rings)- sugar attached to N9 of base

Question 14

bases couples are attached to ribose or pentose through B glycosidic bond between..

Answer 14

carbon 1’ of the (deoxy)ribose and the N9 of a purine or N1 of a pyrimidine

Question 15

bonding in nucleotide

Answer 15

-base attached to carbon 1, phosphate attached to carbon 5/3

Question 16

human body can synthesise only

Answer 16

10 amino acids-essential acids

Question 17

what is triglyceride

Answer 17

fatty acids usually joined together in groups of 3
-energy storage and insulation

Question 18

steroids

Answer 18

hydrophobic and insoluble in water
-have 4 fused rings
e.g. cholesterol- the precursor to vitamin D, testosterone, estrogen, progesterone, aldosterone, cortisol, and bile salts

Question 19

backbones of DNA and rna

Answer 19

formed by 3’ to 5’ phosphodiester linkages

Question 20

3’ to 5’ dna

Answer 20

-backbones formed from 3’ to 5’ phosphodiester linkages
-enzyme will read from 3’ to 5’ direction, but write down from 5’ to 3’ direction for new strand

Question 21

dna methylation

Answer 21

DNA methylation regulates gene expression by recruiting proteins involved in gene repression or by inhibiting the binding of transcription factor(s) to DNA.

Question 22

mode of dna replication

Answer 22

semiconservative and bidirectional

Question 23

Which is a general property of both nucleosides and nucleotides?

Answer 23

Both contain a pentose in the form of a furanose.

Question 24

The pentose in nucleotides are:

Answer 24

In beta furanose form

Question 25

The enzyme that elongates chromosomes by adding repeated sequences to the end of existing chromosomes during replication in eukaryotes is:

Answer 25

Telomerase

Question 26

Which of the following statements about the E. coli chromosome is correct?

Answer 26

Replication begins at oriC.
The E. coli chromosome is a single replicon.

Question 27

what direction is proofreading (i.e. correcting replication errors) during DNA replication by DNA polymerase III?

Answer 27

3’ - 5’ exonuclease activity

Question 28

What is the name of the enzyme that fill in the gap between fragments in the lagging strands?

Answer 28

DNA polymerase I

Question 29

What is the primary function of transcription factors?

Answer 29

to assist in bringing RNA pol in close proximity of the promoter and regulate gene expression

Question 30

what does termination in rna transcript involve

Answer 30

Termination often involves a stem-loop structure forming in the RNA transcript

Question 31

What is the role of eukaryotic RNA polymerase I?

Answer 31

Transcription of the major rRNA transcript

Question 32

In which of the following would you find telomeres?a) Human mitochondrial DNA
b) Human chromosomes
c) Bacterial chromosomes
d) mRNA
e) tRNA

Answer 32

human chromosomes