Thread Of Life

Question 1

DNA description

Answer 1

Double-stranded helix

Made from: sugar (deoxyribose) phosphate group and bases

Question 2

Phosphate and sugar groups bonded by

Answer 2

Condensation reaction

Question 3

Base to sugar bonding

Answer 3

Condensation reaction

Question 4

DNA stands held by

Answer 4

H bonding

Question 5

Nucleotide contains

Answer 5

One sugar
One phosphate
One base

Question 6

Nucleotide –> DNA

Answer 6

Condensation polymer

Question 7

What data was used to support final DNA idea

Answer 7

X-Ray crystallography

Question 8

Protein synthesis

Answer 8

DNA is unzipped, code is transcribed into mRNA (complimentary version of code.
mRNA passes from nucleus to cytoplasm where ribosomes translate the code. Codon (3 bases) code for one amino acid
A.a bought to ribosome by tRNA

Question 9

RNA : DNA

Answer 9

RNA
Ribose
U
And single stranded

DNA
deoxyribose
T
Double stranded

Question 10

DNA fingerprinting how it’s done

Answer 10

Sample is obtained and cut using restriction enzymes
Separated using electrophoresis
Each fragment marked with probe
Exposed on X-Ray film, producing pattern of black bars

Question 11

Ownership issues with DNA fingerprinting

Answer 11

Who should have access to personal genetic information?
Who owns and controls genetic information?
Who owns genes and other pieces of DNA?

Question 12

DNA testing issues with DNA fingerprinting

Answer 12

Should parents have the right to have their children tested?
Should tests be performed for genetic diseases?
Should an individual always be given his/her genetic info?

Question 13

Rate of reaction =

Answer 13

Change in conc of reactant or product / reactant

Question 14

Rise in temperatures affect on k

Answer 14

Increases it

Question 15

Concentrations time graph and orders

Answer 15

\ = 0
Constant half life (L) = first
Half life not constant (L) = second

Question 16

Rate - concentration graph

Answer 16

– = 0
/ = 1
Curve upwards (conc^2 = /) = second order

Question 17

What’s an intermediate?

Answer 17

Chemical formed and destroyed during the course of the reaction

Question 18

Rate determine step and order of reactants

Answer 18

Reactants in rate equation are in rate determine step

Question 19

Stereoisomers :

Answer 19

Same molecular formula and atoms bonded in same order but arranged differently in space. 2 examples : E/Z and optical

Question 20

Chiral centre

Answer 20

4 different atoms or groups of atoms attached to it

Optical isomers/enantionemers

Question 21

What’s a racemic mixture

Answer 21

50:50 mixture of d- and l- optical isomers

Question 22

How do optical isomers behave differently

Answer 22

Behave differently in the presence of other chiral molecules

Optically active molecules rotate the plane of plane-polarized light in different directions.
Laevorotatory (l-) rotates anti clockwise
Dectrorotatory (d-) rotates light clockwise

Question 23

Why are amino acids bifunctional

Answer 23

Contains both amino and carboxyl functional group. When both on same C = alpha amino acid

Question 24

zwitterion-

Answer 24

Amino acids

Positive group and negative group at same time

Question 25

Naming dipeptides

Answer 25

Start at NH2 end

Question 26

Primary structure of a.a

Answer 26

Sequence of a.a

Question 27

Secondary structure of a.a

Answer 27

Polypeptide forms aloha helix or beta pleated sheet

Hydrogen bonding

Question 28

Tertiary structure of a.a

Answer 28

Overall shape of a.a
Due to
I’d-I’d
Hydrogen bonding between polar side chains
Ionic bonds between ionizable side chains
Covalent bonds (eg sulfur bridges )

Question 29

Hydrolysis of peptides/proteins

Answer 29

Amide hydrolysis
Reflux
Mod conc acid/alkali

Question 30

How do you identify a.a from t.l.c

Answer 30

Ninhydrin as a locating agent

Question 31

Ph affect on a.a

Answer 31

Disrupts ionic interactions

Question 32

Rate equation for low concentration of substrate

Answer 32

Rate=k[s][e] plenty of active sites for substrate to bind to

Question 33

Rate of reaction at high conc of substrate

Answer 33

Rate = K[e] as all active sites are saturated

Question 34

Why are enzymes good in industry

Answer 34

Specific
Effective at low temp
Work well in aqueous environment
Often convert reactant to product in one step -increases atom economy