2B: proteins and genetic

Question 1

what are proteins

Answer 1

chains of amino acids
- amino acid
monomers linked by peptide bonds in condensation reactions

Question 2

what is the structure mononucleotides

Answer 2

deoxyribose or ribose sugar linked to a phosphate and a bases with phospodiester bonds

Question 3

what is the structure of DNA

Answer 3

two strands of mononucleotide chains ( a polynucleoride) in a double helix structure

Question 4

what is the structure of RNA

Answer 4

one strand of mononucleotide chain (a polynucleotide)

Question 5

how do mononucleotides link together to form polynucleotides

Answer 5

condensation reactions

Question 6

what are the four main structures of a protein

Answer 6

• primary
• secondary
• tertiary
• quaternary

Question 7

what is the basic structure of an amion acid

Answer 7

a carbon attached to a R group, a carboxyl group and a amine group

Question 8

how to differiate amino acids

Answer 8

by their R groups

Question 9

what is a proteins primary structure

Answer 9

sequence of AA in polypeptide chains - linked via peptide bonds

Question 10

what is a proteins secondary structure

Answer 10

alpha helix and beta pleated sheets formed when hydrogen bonds form between the AA chains

Question 11

what is a proteins tertiary structure

Answer 11

the chains are further coiled/folded as more bonds form inbetween the polypeptide chains (hydrogen & ionic, maybe disulfide) and their 3D structure is formed

Question 12

what is a proteins quaternary structure

Answer 12

multiple polypeptide chains (tertiary) assembled together - final 3D structure

Question 13

how significant is primary protein structure

Answer 13

determines 3D structure and properties
- determines which bonds will form and how the protein will fold

Question 14

what are the 2 types of 3D structures of a proteins

Answer 14

globular and fibrous

Question 15

what is the globular structure of a protein

Answer 15

round, compact proteins
- polar hydrophylic parts of the chain on outside of molecule
- hydrophobic parts of the chain face inwards of the molecule
- soluble due to hydrophylic outerlayer

Question 16

what is the fibrous structure of a protein

Answer 16

long insoluble chains coiled around each other in a rope
- triple helix of polypeptide chains held by H+ bonds

Question 17

what are the two parts of protein synthesis

Answer 17

transcription and translation

Question 18

what happens during transcription

Answer 18

an mRNA copy of gene(DNA) is made
- RNA polymerase attach to DNA and H+ bonds between the double helix strands break
- the strands separate and one strand is copied and used as a template for an mRNA copy
- free mononucleotides (bases) are lined next to the copy strand and complimentary base paring takes place forming a complete copy
- strands are joined together with RNA polymerase forming mRNA molecule
- RNA polymerase meets stop codon and will detatch from DNA
- mRNA moves out of the nucleus via the nuclear pore and attatches to a ribosome in the cytoplasm to be translated

Question 19

what happens during translation

Answer 19

protein AA sequence is translated
- transfer RNA carry AA to the ribosomes
- tRNA w/ a anticodon connect to complementary codon
- amino acids are then joined together with peptide bonds
- tRNA moves away and ribosome moves to next codon and the process repeats
- AA join together to form polypeptide chain

Question 20

what is the degenerate code

Answer 20

more codons than corresponding AA therfore some genetic mutations may not have an effect due to AA codons
- similar structure
- code for same AA
- not at the active site therefore has no effect