m1 + 2 lect. - DNA

Question 1

where is DNA (Deoxyribonucleic Acid) located?

Answer 1

nucleus of the cell

Question 2

what are the complementary base pairs in DNA?

Answer 2

adenine - thymine

guanine - cytosine

Question 3

what shape is a DNA strand in?

Answer 3

double helix

Question 4

what is a nucleotide? what is it made of?

Answer 4

one piece of DNA

a base pair (C, G, A, or T), a phosphate, and a sugar

Question 5

what does DNA allow us to do?

Answer 5

allows us to store and copy information

Question 6

in the nucleus of our cells, what functional states of DNA can be found?

Answer 6

chromosomes
chromatin

Question 7

in what functional state are chromosomes?

Answer 7

tightly packed strand, unusable and only seen in cell division

Question 8

in what functional states are chromatids?

Answer 8

loose strand, usable and seen during interphase

Question 9

what is a gene?

Answer 9

a sequence that codes for a protein

Question 10

what does DNA contain?

Answer 10

• information which defines all cellular functions
• produces all the proteins in the cell and body
• made from nucleotides

Question 11

4 parts to a strand of DNA?

Answer 11

-telomeres
-exons/genes
-introns
-epigenome

Question 12

telomeres

Answer 12

• are the end segments of DNA strands, non-coding
• allow DNA to be replicated
• are protective tips – lose alot every replication

Question 13

exons/genes

Answer 13

• coding segments of DNA —> give us traits = proteins

Question 14

introns

Answer 14

• non-coding segments
• protect the gene
• label the gene (promoter)

Question 15

epigenome

Answer 15

• covering of the gene
• will activate or deactivate the gene
• identify what cell type each becomes

Question 16

life cycle of the cell

Answer 16

Interphase:
- G1 phase
- S phase
- G2 phase

Mitotic phase:
mitosis

Question 17

what are the phases in mitosis?

Answer 17

• Prophase
• Metaphase
• Anaphase
• Telophase

Question 18

what is cytokinesis?

Answer 18

division of the cytoplasm

Question 19

what happens in the interphase stages?

Answer 19

G1 phase - (2n) growth and preparation for DNA replication
S phase - (2n —> 4n) DNA replication
G2 phase - (4n) growth and preparation for division of DNA

Question 20

what happens in the mitotic phase?

Answer 20

mitosis - (2n - 2n) division of DNA

Question 21

what regulates mitosis?

Answer 21

• nutrition
• age
• hormones
• available space
• genetics - P53 genes

Question 22

semi-conservative replication:

Answer 22

• carried out in nucleus during the S-phase of Interphase
• DNA is usually wrapped around histones - protection and organization

Question 23

steps of semi-conservative replication?

Answer 23

1) helicase enzymes unravel the DNA
—> creating replication bubble
2) replisomes act as initiating sites
- RNA primers - starting point
3) DNA Polymerase enzyme forms new strands
- lead strand forms continuously
- lag strand forms segments
4) segments of DNA are complete, DNA ligase => checks errors and fuse segments

Question 24

is DNA or RNA responsible for protein synthesis?

Answer 24

RNA

Question 25

what is RNA made from? what form is it found in?

Answer 25

ribonucleic acid
single strands

Question 26

what are the bases of RNA?

Answer 26

Adenine - Uracil
Guanine - Cytosine

Question 27

what are the three forms of RNA?

Answer 27

mRNA
rRNA
tRNA

Question 28

what is mRNA?

Answer 28

messenger RNA - copy “blueprint” of DNA

Question 29

what is rRNA?

Answer 29

ribosome RNA - building site “factory site” of protein synthesis

Question 30

what is tRNA?

Answer 30

transfer RNA - carries amino acids to factory site “logistics”

Question 31

protein synthesis starts at the:

Answer 31

intron –> promotor –> gene —> actin

Question 32

protein synthesis: step one

Answer 32

DNA separated by helicase enzymes at the promotor of that gene

Question 33

protein synthesis: step two

Answer 33

RNA nucleotides begin to assemble in base pairs
- RNA copies the template strand of DNA only

Question 34

what are the three beginning nucleotides called?

Answer 34

a triplet

Question 35

in protein synthesis what are the three corresponding nucleotides of RNA called that match DNA?

Answer 35

a codon

Question 36

at the beginning of the mRNA strand there is a set of three bases, what are they called? and what are they?

Answer 36

-start codon
- AUG

Question 37

what is at the end of a mRNA gene strand? and what does it do?

Answer 37

-stop codon
-ends the transcription process

Question 38

in what order do the codons move in the ribosome sites?

Answer 38

• A site
• P site
• E site