SAC 2 (cell cycle) Flashcards
1
Q
Interphase
A
- G1,S,G2
- cell spends most of it’s life in interphase
2
Q
G1
A
- cell growth
- chromosomes exist as chromatin (open form)
3
Q
S phase (Synthesis)
A
- DNA replication
- chromosomes exist as chromatin (open form)
4
Q
G2
A
- prepares for divison
- chromosomes exist as chromatin (open form) at the start of G2
- chromosomes condense (closed/coiled form) during G2 and finish condensing in prophase
5
Q
Mitosis - Prophase
A
- chromosomes finish condensing (closed/coiled form)
- condense for protection
- spindle fibres produced
6
Q
Mitosis - Metaphase
A
- chromosomes line up along the equatorial plate (any order)
- spindle fibres attach to the centre of each chromosome
7
Q
Mitosis - Anaphase
A
- spindle fibres pull chromosomes towards opposite poles of the cell
- chromatids are pulled apart from each other
8
Q
Mitosis - Telophase
A
- nuclear membrane reforms
- chromosomes decondense
- chromosomes revert back to chromatin to form nuclear membrane
9
Q
Cytokinesis
A
- cyto means cell
- cells splits into 2 daughter cells
10
Q
Apoptosis
A
- programmed (deliberate) cell death
- is to prevent cells with DNA damage from continuing replication
- INTERNAL - enzymes (capases) are released from the mitochondria
- EXTERNAL - a signal (death ligand) binds to the outside of the cell and then capases are triggered
11
Q
Apoptosis steps
A
- capases released break down DNA and the cell cytoskleteton
- cell starts to bleb (blebbing)
- cell blebs break up into vesicles
- vesicles are engulfed by immune cells by endocytosis
12
Q
Nucleotide structure
A
- subunit - monomer
- phosphate (circle)
- deoxyribose sugar (pentagon)
- nitrogen base (A,T,C,G) (rectangle)
13
Q
DNA structure
A
- is a polymer
- made up of many subunits (monomer is the subunit)
- the monomer is a nucleotide
14
Q
complementary base pairing rule
A
- Adenine bonds with Thymine (2 hydrogen bonds)
- Cytosine bonds with Guanine (3 hydrogen bonds)
- hydrogen bond is attraction between the base pairs
15
Q
rungs and backbone
A
rungs - base pairs
backbone - sugar and phosphate