Unit 1 Flashcards
(137 cards)
1
Q
proteomics is
A
study of the proteome
2
Q
proteome is
A
entire set of proteins expressed by genome
3
Q
what is larger proteome or genome and why
A
proteome because of alternative splicing and post translational modification
4
Q
types of RNA
A
rRNA mRNA tRNA non coding RNA
5
Q
transcriptome
A
all mRNA molecules produced by genome
6
Q
how to find out transcriptome
A
microarray analysis
7
Q
amino acids are made of
A
carboxyl group, hydrogen, carbon, amine group, R group
8
Q
environmental factors that affect protein shape and function
A
ph and temperature
9
Q
binding of proteins cause a ____ change which can consequently change the function. this can/cannot be reversible
A
conformational , can
10
Q
when binding, shapes must be ______
A
complementary
11
Q
primary structure
A
order in which amino acids are synthesised into amine polypeptides
12
Q
types of secondary structure
A
alpha helix, beta sheets, turns, hydrogen bonds between atoms of same chain
13
Q
alpha helix
A
spiral, r groups sticking out
14
Q
beta sheets
A
running alongside each other, can be antiparallel or parallel
15
Q
what determines whether beta sheet is parallel or antiparallel
A
N and C terminus. if they are at opposite termini then they are parallel
16
Q
turns
A
reverse the direction of the polypeptide chain
17
Q
tertiary structure
A
R GROUPS. folding and shape depends on these. bonding can influence folding- ionic, disulphide, hydrogen, van Der Waals, add prosthetic group eg haem
18
Q
quartenary structure
A
links subunits (polypeptide chains) together
19
Q
ionic bonds are
A
electrostatic
20
Q
hydrogen bonds are
A
electromagnetic
21
Q
disulphide bonds are
A
covalent
22
Q
folding can hide the ____ R groups and have the _____ R groups on the outside
A
hydrophobic, hydrophilic
23
Q
how are peripheral proteins held in place
A
charged or polar amino acids or hydrophobic interactions
24
Q
how are integral proteins held in place
A
hydrophobic interactions
25
integral proteins
some transmembrane- channels, transporters, some not
26
fluid mosaic model is
membrane. phospholipid bilayer- moves around a lot, mosaic because of integral proteins, peripheral proteins
27
phospholipid bilayer has
hydrophilic polar head, hydrophobic non polar tail
28
ligands are
substances that can bind to a protein
29
what allows substances to bind to proteins
R groups and complementary binding sites
30
DNA binds to proteins a lot. Name one protein it binds to
histones
31
what part of DNA binds to protein
sugar phosphate backbone because negatively charged
32
DNA wraps around histones to form
nucleosomes
33
what environmental factors affect ligands
ph and temp
34
cooperativity
binding increases affinity of remaining sites
35
allosteric enzymes
modulators bind at secondary site, changing affinity of active site (increase or decrease)
36
phosphorylation
addition or removal of phosphate from R groups which causes a reversible conformational change
37
phosphorylation is a type of ___ _______ ______
post translation modification
38
phosphorylation regulates ____/_____ activity
enzyme/ receptor
39
which enzyme catalyses dephosphorylation
phosphatase
40
which enzyme catalyses phosphorylation
kinase
41
what enzyme uses ATP for phosphorylation
ATPases
42
water channels
aquaporins
43
facilitated transport
involves conformational change. does not require energy
44
transmembrane proteins function
control the concentration of ions and other molecules within the cell
45
voltage gated channels
controlled by changes in ion concentration.
46
ligand gated channels
neurotransmitters required to open binds to receptor site
47
active transport
conformational change requires energy from hydrolysis of ATP
48
sodium potassium pump
3 Na out 2 K in. phosphorylation of ADP + Pi uses active transport
49
glucose uses ____ to transport
facilitated transport
50
signal transductions
receptor proteins convert extracellular chemical signals to specific intracellular response
51
signal transductions can (3)
activate proteins that regulate gene transcription, rearrange cytoskeleton, change uptake/secretion of molecules
52
G proteins
transmits signals from outside to inside the cell
53
G proteins are active by
GTP
54
G proteins are inactivated by
GDP
55
sodium potassium pump is used for (4)
maintaining osmotic balance, glucose symport, resting potential neurons, ion gradient for kidney tubules
56
glucose symport
sodium and glucose in. glucose against conc gradient so need energy from sodium going down gradient
57
membrane potential
electrical potential difference (voltage) across plasma membrane
58
resting potential value
-70mV
59
minus sign for voltage means
inside of cell is negative relative to outside
60
the resting potential is generated and maintained by
sodium potassium pump
61
nerve transmission is
a wave of depolarisation of resting potential
62
depolarisation is stimulated by
neurotransmitter opening ligand gated ion channels, causing resting potential to increase and action potential to begin
63
order of action potential
neurotransmitters act as ligand and open ligand gated channel, allows ions to enter and voltage increases, voltage gated channels open, wave of depolarisation, wave passes, channels close, restore resting potential
64
depolarised value
40mV
65
polarised
more K+ inside. negative membrane potential
66
graded potential
small change
67
action potential
big change
68
graph of action potential
depolarisation, repolarisation, hyperpolarisation
69
refractory period
axon can't respond to any other stimulus
70
rod cells
changes due to light intensity, longer than cones, very sensitive to light
71
cone cells
less sensitive to light, absorb different wavelengths of light, colours
72
rhodopsin
combination of retinal and opsin
73
photoreceptor proteins are
light sensitive and sense and respond to light
74
how rhodopsin reacts to photon of light
becomes excited, nerve impulse generated, G protein activated, enzymes activated, ion channels close, sodium leak inward, membrane potential increases, hyper polarisation stimulates nerve impulse
75
communication between cells caused by
extracellular signalling molecules, receptors and responses
76
receptor molecules are
on target cells and have binding site for signalling molecule,
77
the signals are s____
specific for specific receptors
78
signal transduction occurs when
signalling molecules bind to and activates specific receptor which is on surface or within cell
79
hydrophobic signalling molecules can/cannot pass through membrane
can
80
examples of hydrophobic signalling molecules
steroid hormones eg oestrogen and testosterone and thyroxine
81
hydrophilic signalling molecules can/cannot pass through membrane
cannot but signal can be transduced
82
the binding of insulin triggers
GLUT4 glucose transporters to cell membrane of fat and muscle cells and this facilitates uptake of glucose into cells
83
type 1 diabetes
due to lack of insulin production
84
type 2 diabetes
due to loss of insulin receptor proteins. exercise triggers GLUt4 too so can help
85
Cytoskeleton is made of
Proteins. Microfilaments, microtubules, intermediate filaments
86
Cytoskeleton is
Network of proteins extending throughout cytoplasm constantly breaking down and reforming
87
Function of cytoskeleton
Provide mechanical support
Provide anchorage for organelles
Enable whole cell to move
Enable organelles within cell to move
88
Microtubules are
Hollow, straight cylinders made of tubulins
89
Types of tubulin
Alpha and beta
90
Tubulin governs...
Location and movement of membrane bound organelles
91
Microtubules originate from
Microtubules organising centre MTOC in centrosome
92
Spindle fibres are formed by
Microtubules
93
Cell cycle order
M
G1
S
G2
94
Decreasing rate of cell cycle causes
Degenerative diseases
95
G1 phase
Growth phase where proteins are synthesised
96
S phase
Cell continues to grow and copies chromosomes in preparation for mitosis
97
G2
Growth phase where proteins are synthesised
98
M phase
2 part- mitosis and cytokinesis
99
Parts of mitosis
```
PMAT
prophase
Metaphase
Anaphase
Telophase
```
100
First part of cell cycle is collectively called
Interphase
101
Spindle fibres join to ____ to pull apart chromatids
Kinetochore
102
Cytokinesis
Separation of cytoplasm into daughter cells
103
G1 checkpoint
Occurs at end of G1 and checks for sufficient growth and other conditions satisfied
104
If don’t pass G1
G0 phase which is non dividing phase
105
S phase checkpoint
None
106
G2 checkpoint
Occurs at end of G2 DNA replication must be completed
107
M phase checkpoint
Occurs during metaphase and controls entry to anaphase. Checks chromosomes are aligned correctly and ensure each daughter cell receive correct number of chromosomes
108
CDKs are
Cyclin dependant kinases. Cause phosphorylation of proteins that stimulate cell cycle if enough phosphorylation is reached, can proceed
109
Types of regulatory proteins
Retinoblastoma Rb and P53
110
Retinoblastoma
If non phosphorylation then restricts progression from G1 to S phase. Phosphorylation inhibits Rb activity so it can no longer bind to transcription factor so transcription factor is released and genes are trans opted for S phase to begin
111
P53
Repairs, arrests or causes cell death.
| Is there if DNA damage or cell damage
112
If mutation in p53
Cancer
113
Apoptosis is
Destruction of cells. Programmed cell death
114
Death signals results in activation of enzymes called
DNAases and Proteinases (caspases)
115
DNAases
Catalyse breakdown of DNA
116
proteinases
Bring about degradation of cellular proteins
117
Fragments at end of apoptosis are
Engulfed by phagocytes
118
Extrinsic death signals
Lymphocytes can express death activator ligand called Fas which activated protein cascade that introduces caspases and causes apoptosis
119
Intrinsic death signal
DNA damage
120
Receptor proteins for steroid hormones
Transcription factors
121
What happens to receptor protein when a signal molecule binds
G protein activation
Enzyme activation
Ion channels close
122
Role of ligand gated ion channels in transmission of nerve impulses
Neurotransmitter triggers opening of ligand gated ion channels, if sufficient ion movement occurs then voltage gated ion channels open and this triggers sequence of voltage gated channels to open and a wave of depolarisation.
123
Intracellular responses as a result of signal transduction
Activation of enzyme
Activation of G protein
Change in uptake or secretion of molecules
Rearrangement of cytoskeleton
124
Steroid hormones are hydrophobic/hydrophilic
Hydrophobic
125
Insulin is hydrophilic/hydrophobic and steroid/ peptide
Hydrophilic and peptide
126
Tubulin is integral/ globular
Globular
127
types of amino acid
acidic, basic, polar, hydrophobic
128
r group of acidic amino acid
carboxylic acid COOH
129
r group of basic amino acid
amine group NH2
130
r group of polar amino acid
hydroxide group OH
131
r group of hydrophobic amino acid
hydrocarbon CH (benzene ring)
132
acidic amino acids are what charge
negatively
133
basic amino acids are what charge
positive
134
polar amino acids are what charge
slightly charged and hydrophilic
135
hydrophobic amino acids are what
non polar
136
peptide bonds are formed by what reaction
condensation H20 is removed
137
what does peptide bond look like
N-H- C=0
