13O- Amino Acids Protien DNA

Question 1

Amino acid properties

Answer 1

Acidic properties, carboxylic acid group loses H+
Basic properties, amine group accepts H+

Question 2

What’s a zwitterion

Answer 2

Permenant +ve and -ve charge, no overall charge

In acid, line pair on NH2 accepts H+, +ve charged
In alkali, OH group loses H+, -ve charged

Question 3

Glycine in acidic conditions

Answer 3

NH3+- CH2- COOH

Question 4

Glycine in alkali conditions

Answer 4

NH2-CH2-COO-

Question 5

Properties of amino acid

Answer 5

High MPs and BP, strong ionic bonds between opposite charged ions
Dissolved in water

Question 6

What’s a protein

Answer 6

Sequence of amino acids, joined by peptide links

Question 7

What’s a peptide link

Answer 7

Amine group of 1 amino acid reacts with carboxylic acid group of another amino acid
NH-CO

Question 8

What’s the primary structure of proteins

Answer 8

Sequence of amino acids along a protein chain, held by covalent bonding, relatively stable

Question 9

What’s the secondary structure of a protein

Answer 9

Protein chain forms a helix (alpha helix) or pleated sheet (beta pleated sheet), held in place by hydrogen bomding between C=O and NH groups, disrupted by pH change or heat

Question 10

What’s the tertiary structure of a protein

Answer 10

The alpha helix or beta pleated sheet can fold into a 3D shape, held by H bonding, ionic bonds, sulphur-sulphur (disulphide) bonds and van der waals, many fold into globular shapes

Question 11

Why are hydrogen bonds and sulphur-sulphur bonds important in proteins

Answer 11

Proteins are complex shapes, held in position by hydrogen bonds and sulfur-sulfur bonds, these stamped are imperative for their function

Question 12

What does the hydrolysis of a peptide link produce

Answer 12

Constituent amino acids

Question 13

How can amino acids be separated and identified

Answer 13

Thin layer chromatography

Question 14

Glycine + glycine

Answer 14

NH2-CH2-C=ONHCH2COOH

Question 15

What’s an enzyme

Answer 15

Protein

Question 16

How do enzymes work as catalysts

Answer 16

Globular proteins
Substrate fits into active site, complimentary shape, bond to active site temporarily through intermolecular forces, these forces promote movement of e- lowering activation energy react, lock and key

Question 17

What’s a stereo specific active site

Answer 17

Active site only catalyses reactions with one enantiomer as they are specific to substrates

Question 18

What’s an enzyme inhibitor

Answer 18

Molecule which binds to enzymes active site, blocks the substrate from forming an enzyme substrate complex

Question 19

What’s computer modelling

Answer 19

Allows for prediction of the shape of a protein before synthesis, predict properties, design drugs for medical conditions

Question 20

What’s a nucleotide made of

Answer 20

Phosphate ion bonded to 2-deoxyribose bonded to either adenine, cytosine, guanine or thymine

Question 21

Describe the structure of DNA

Answer 21

Polymer of nucleotides linked by covalent bonds between phosphate group of one nucleotide and the 2 deoxyribose of another, forms sugar phosphate polymer chain, bases attached to sugar in chain

Question 22

How does DNA have two complimentary strands

Answer 22

Hydrogen bonding can only occur between adenine and thymine, and guanine and cytosine this means that one strand will have another strand with a base sequence it forms hydrogen bonds with
Eg ACT has a complimentary strand TGA

Question 23

How is a nucleotide bonded

Answer 23

O from OH on phosphate bonds to CH2 (carbon 5) on 2-deoxyribose (H2O molecule lost)
N from NH on a base bonds in place of the OH from 2-deoxyribose (carbon 1) (H2O molecule lost
O from OH on 2-deoxyribose (carbon 3) bonds to the O on a phosphate of another nucleotide (produces H2O)

Question 24

How can you locate amino acids on a chromatogram (TLC)

Answer 24

Use developing agents ninhydrin or uv light, measure distance travelled by solvent and travelled by spot
Rf= distance moves by spot/ distance moves by solvent
Compare this arc value to arc values of known amino acids

Question 25

What’s cisplatin

Answer 25

Anti cancer drug

Question 26

What’s the shape of cisplatin and it’s formula

Answer 26

Square planar

Pt(NH3)2Cl2

Question 27

How does cisplatin work

Answer 27

Ligand replacement reaction, dative covalent bonds from N atoms on two adjacent guanine bases on a DNA strand
Bonding to strands of DNA, distorts their shape, prevents replication of cell

CGATCTTAG
| |
Pt
(NH3)2

Question 28

Benefits and adverse effects of cisplatin and why the drug causes adverse effects

Answer 28

Adverse effects- Cisplatin can bond to DNA in healthy cells that replicate quickly
hair cells replicate quickly causing hair loss
Benefits
90% effective in treating testicular cancer, slowing down progression