MCGB Revision Lecture 1a Flashcards
(100 cards)
1
Q
which cells is the nucleus not found
A
RBC and platelets
2
Q
where are pronucleus’ found
A
ovum and spermatozoa
3
Q
how big is a nucleus
A
6nm
4
Q
how to substances such as mRNA leave the nucleus?
A
via nuclear pores
- bilayer is very selective
5
Q
role of nucleolus found at the centre the nucleus
A
rRNA synthesis and ribosomal subunit proteins
6
Q
nucleoplasm
A
cytoplasm of the nucleus
7
Q
chromatin is found
A
in the nucleoplasm
8
Q
heterchromatin (dark)
A
condensed
9
Q
euchromatin (white)
A
non- condensed
10
Q
where are mitochondria not found
A
RBC- can only anaerobically respire
–> don’t use the oxygen they are carrying
11
Q
outer membrane of mtichodnria
A
smooth
12
Q
inner membrane of mitochondria called
A
cristae
- ETC (ATP production)
13
Q
what happens in the matrix of the mitochondria
A
link reaction and krebs cycle
14
Q
link reaction
A
conversion of pyruvate to acetyl co A
15
Q
mitochondria has it own
A
DNA and ribosomes
- endosymbiotic theory
16
Q
RER and SER present in all cells but
A
RBC
17
Q
RER and SER structures
A
flattened sacs called cisternae
18
Q
diff between RER and SER
A
RER around nucleus and SER around RER or in cytosol
19
Q
function of RER
A
protein synthesis and packaging into vesicles
20
Q
function of SER
A
detoxification, fatty acid synthesis, disulphide bond formation, storage of calcium, cholesterol metabolism
21
Q
Golgi structure
A
flattened sacs making up cisternae
22
Q
cis golgi
A
incoming vesicles and processing (glycosylation, sulfation, nitrosylation)
23
Q
Golgi stack
A
cis, middle and trans cisterna
24
Q
trans golfi
A
sorting vesicles and exiting
25
role of Golgi
* Receiving, processing packaging and shipping of proteins
| * Distribute to other organelles or out of the cell by exocytosis
26
lysosomes not found in
RBC
27
structure of lysosomes
Single membrane formed from the budding off Golgi apparatus
28
pH of lysosome
pH5
29
what are found within lysosomes
Hydrolases – protease, lipase, nuclease and polysaccharidases
30
function of lysosomes
Cleavage of organic substance and the destruction of dead organelles
31
lysosome are similar to
peroxisomes formed from the budding of SER. They synthesis bile acids and contain catalases and other oxygen dependent enzymes. They are also found in plant cells
32
cytoskeleton found in
all cells
- microtubules
- microfilaments
- intermediate filaments
33
microtubules
- polymers of globular tubulin
- needed for centriole formation in cell division - maintains shape of cell and anchors organelles -form basal bodies to develop motile cilia
34
microfilaments
- polymers of globular actin
| - cell to cell interactions and cells to matrix
35
intermediate filaments
- fibrous protein
| - maintains cell shape and cell to matrix interactions
36
bacterial cells have both
plasma membrane and cell wall
37
bacterial cell structures
- capsule
- pili
- flagellum
38
outer coat of virus called
envelop, covered in envelope proteins
39
viral genes enveloped in
capsid
40
what comprises nucleic acid
sugar, phosphate head and base
41
reaction when nucleic acids polymerise
Condensation reaction between the hydroxyl group on Carbon 3 of one nucleotide to the phosphate group on the adjacent nucleotide, producing water as a by product.
42
5' end of DNA
phosphate head
43
3' end
hydroxyl end
44
polarity
ability to create dipoles due to unequal distribution
45
5' end is
partially negative due to the electronegative oxygen
46
3' end is
partially positive due to the end of the hydrogen being starved of its electrons ti oxygen
47
purines
adenine and guanine
48
pyrimidines
thymine and cytosine and uracil
49
how many hydrogen bonds between A and T
2 hydrogen bond
50
how many hydrogen bonds between G and C
3 hydrogen bonds
| ◦Strongest bond
51
how many hydrogen bonds between A and U
◦2 hydrogen bond
52
difference between RNA and DNA
deoxyribose sugar in DNA
ribose sugar in RNA
53
diff between deoxyribose and ribose
Deoxyribose has H group on 2' carbon position
ribose has hydroxyl group in 2' carbon position
54
DNA nucleoside name of the base adenine
deoxyadenosine
55
DNA nucleoside name of the base guanine
deoxyguanosine
56
DNA nucleoside name of the base thymine
deoxythymidine
57
DNA nucleoside name of the base cytosine
deoxycytidine
58
DNA nucleotide name for adenine
deoxyadenosine monophosphate (dAMP)
59
DNA nucleotide name for cytosine
deoxycytidine monophosphate (dCMP)
60
DNA nucleotide name for guanine
deoxyguanosine monophosphate (dGMP)
61
DNA nucleotide name for thymine
deoxythymidine monophosphate (dTMP)
62
RNA nucleoside name of the base adenine
adenosine
63
RNA nucleoside name of the base uracil
uridine
64
RNA nucleoside name of the base cytosine
cytidine
65
RNA nucleoside name of the base guanine
guanosine
66
RNA nucleotide name for adenine
adenosine monophosphate (AMP)
67
RNA nucleotide name for cytosine
cytidine monophosphate (CMP)
68
RNA nucleotide name for uracil
uridine monophosphate (UMP)
69
RNA nucleotide name for guanine
guanosine monophosphate (GMP)
70
structure of DNA
double helix
71
how much DNA packaged into 6nm nucleus
2m
72
how is DNA packaged
DNA wraps around histones to form nucleosomes - 'beads on a string', this are then further condensed to form solenoids--> firmly compressed to form chromosomes
73
the human genome
22 autosomes
| 2 sex chromosomes
74
p arm on a chromosome
short
75
q arm on a chromosome
long
76
how many structures of chromosomes
4
- telocentric
- acrocentric
- submetacentric
- metacentric
77
telocentric
centromere at the the top the q arm (not found in humans)
78
acrocentric
centromere near the top of the top
| - short p arm
79
submetacentric
centromere near the centre- shortish p arms
80
metacentric
centromere right in the middle of p and q arms
81
beads on a string structure
euchromatin
- more accessible for replication
- gene expression
82
solenoids structure
heterochromatin
- less accessible for replication
- genes are silenced
83
methylation of DNA (methyl added to cysteine)
reduces expression
84
acetylation of histones
increases expression
85
cell cycle summary
M --> G1 --> S --> G2
86
where does G0 occur
after mitosis
| - temp arrest
87
G1
11h
| cellular contents excluding the chromosomes are duplciated
88
S
8 h
| each of the 46 chromosomes is duplicated by the cell
89
G2
4h
| the cell double checks the duplicated chromosomes and makes repairs
90
Mitosis
1hr
| production of two identical daughter cells
91
interphase
all phases except mitosis
92
where are the checkpoints in cell cycle
G1
G2
Spindle checkpoing
93
G1 checkpoint
checks for
- cell size
- cell nutrients
- growth factors
- DNA damage
94
G2 checkpoint
check for
- DNA damage
- DNA replication completeness
95
Spindle checkpoint
check all chromosomes are attached to the spindle at the metaphase plate
96
which proteins have a role in controlling cell cycle
CYCLINS
| - activate cyclin dependent kinases
97
cyclins are activated by
growth factors
98
cyclin dependent kinase (CDK) complexes
activate transcription factor E2F
99
E2F induces
S phase proteins to trigger DNA replication
100
cyclins are different for each
stage of cell cycle
e. g. G1 cyclin
e. g. G1/S cyclin
e. g. S cyclin
e. g. M cyclin
