DNA

Question 1

Organisation of DNA

Answer 1

Double helix
Sugar-phosphate backbone
Complementary nitrogenous bases:
Adenine - tyrosine
Guanine - cytosine

Question 2

Protein Synthesis

Answer 2

Cells constantly synthesise proteins; used for cell functioning or exported from cell

Question 3

Proteome

Answer 3

All proteins made by the cell

Question 4

Proteomics

Answer 4

study of proteins in a cell

Question 5

Transcription

Answer 5

DNA to RNA

Question 6

Translation

Answer 6

RNA to protein

Question 7

The central dogma

Answer 7

flow of information from DNA to RNA

Question 8

DNA vs RNA

Answer 8

Sugar; ribose vs deoxyribose
Single stranded
Contains uracil vs thyamine

Question 9

RNA

Answer 9

the stage between DNA and protein; initiated by transcription factors

Question 10

Exons

Answer 10

coding sections of RNA

Question 11

Introns

Answer 11

non-coding sections of RNA

Question 12

Types of RNA

Answer 12

Messenger RNA
Ribosomal RNA
Transfer RNA

Question 13

Messenger RNA

Answer 13

translated in cytoplasm to make proteins

Question 14

Ribosomal RNA

Answer 14

makes up ribosomes

Question 15

Transfer RNA

Answer 15

translates mRNA into amino acid peptide

Question 16

Transcription Process

Answer 16

• DNA strands are separated
  
  • RNA polymerase binds at promoter region
  • RNA polymerase catalyses formation of mRNA chain using DNA as a template, follows the rules of complimentary base pairing
  • Transcription ends at terminator sequence
  • mRNA exits nucleus through nuclear pores

Question 17

Translation

Answer 17

Occurs in cytoplasm by ribosomes
mRNA carries genetic info from nucleus to ribosomes
Begins at start codon

Question 18

Post-translational modification

Answer 18

chemical modification of protein following translation - may attach to other functional groups, may be shortened

Question 19

Phosphorylation

Answer 19

controls the behaviour of the protein; activating/inactivating enzyme

Question 20

Side chains (protein structure)

Answer 20

non-polar and hydrophobic, hydrophillic, positively/negatively charged
interactions between side groups and peptide bonds affects shape of protein

Question 21

Classification of aa chains

Answer 21

2+ aa’s - peptide
10+ aa’s - polypeptide
50+ aa’s - protein

Question 22

Primary protein structure

Answer 22

sequence of aa’s linked by peptide bonds

Question 23

Seconday protein structure

Answer 23

proteins fold forming secondary structures due to side chains
Alpha helices and beta pleated sheets = regular folding patterns

Question 24

Tertiary protein structure

Answer 24

3D shape determined by folding of secondary structure

a-helices and b-sheets foldto form structures held by bonds between aa’s spaced far apart in peptide chain

Question 25

Quanternary protein structure

Answer 25

combined 3D structure of 2+ polypeptide chains | eg haemoglobin

Question 26

Globular proteins

Answer 26

``` chains fold into compact shape Usually water soluable Mobile Chemically active Crucial in biological processes ```

Question 27

Fibrous proteins

Answer 27

Simple, elongated Insoluable, stable Provides mechanical support, tensile strength Abundant outside of cell, make up matrix between cells eg. collegen, keratin, elastin

Question 28

Somatic cell

Answer 28

biological cell forming body of multicellular organism - most cells - 46 chrs - mitosis

Question 29

Germ cell

Answer 29

give rise to gametes - located in ovaries and testes - meiosis

Question 30

Gamete

Answer 30

cells fused during sexual reproduction

Question 31

Interphase

Answer 31

between cell divisions replication of DNA Replication of DNA Normal cell activities

Question 32

Mitosis

Answer 32

results in production of two cells by division of mother cell to two genetically identical daughter cells

Question 33

Mitosis - stages

Answer 33

``` Interphase Prophase Metaphase Anaphase Telophase ```

Question 34

Cytokinesis

Answer 34

division of cell cytoplasm

Question 35

Chromatin

Answer 35

DNA complexed with proteins (histones)

Question 36

Locus

Answer 36

location of a gene on a chrs

Question 37

Prophase

Answer 37

chromatin condenses into chrs, centrioles migrate to ends of cell, spindle fibres attach to centromeres, nuclear envelope disintegrates

Question 38

Metaphase

Answer 38

chrs are aligned at nuclear equator

Question 39

Anaphase

Answer 39

spindle fibres separate chromatids, 2 sets of chrs move to separate ends of cell, cytokinesis begins

Question 40

Telophase

Answer 40

nuclear envelope reforms around each set of chrs, chromosomes decondense into chromatin, cytokinesis continues

Question 41

Cells with high mitosis rate

Answer 41

skin, gastrointestinal tract, oral cavity, anus, cervix and vagina

Question 42

Cells with normal mitosis rate

Answer 42

in-utero, puberty, wound healing, RBC

Question 43

Cells with slow mitosis rate

Answer 43

brain, heart, skeletal muscle

Question 44

Meiosis

Answer 44

Germ cells divide and produce gametes Specialised for sexual reproduction DNA replication followed by 2 cell divisions Produces 4 genetically different daughter cells; * gametes, haploid * one homolog from each homologous pair

Question 45

Meiosis - prophase

Answer 45

Homologous chrs line up DNA is exchanged between adjacent chromatids Sister chromatids are no longer identical Results in exchange of genetic material between maternal and paternal chrs = new gene combination = new human variation