BIOCHEMISTRY Flashcards
1
Q
define an atom
A
smallest unit of an element
2
Q
what does an atom contain
A
nucleus (protons & neutrons)
electrons
3
Q
what is within a nucleus
A
protons
neutrons
4
Q
what charge are protons
A
positive
5
Q
what charge are neutrons
A
neutral
6
Q
what charge are electrons
A
negative
7
Q
what is the atomic number
A
number of protons
8
Q
what is atomic mass measured in
A
Daltons (Da)
9
Q
what is atomic mass
A
gives us the mass of one of the elements atoms
10
Q
how many elements known to make up living organisms
A
26
11
Q
what is covalent bonding
A
the bond formed when atoms share electrons
12
Q
when is a single bond formed
A
when each atom contributes one electron
13
Q
when is a double bond formed
A
when each atom contributes 2 electrons
14
Q
what do organic molecules contain
A
carbon
15
Q
what do inorganic molecules contain
A
NO CARBON (eg water)
16
Q
what is a molecule
A
atoms joined via covalent bonds
17
Q
what is molecular formula
A
symbols
eg H20
18
Q
what is structural formula
A
drawn out with C and H and lines
19
Q
do molecules have a charge
A
no they are neutral
20
Q
do ions have charge
A
yes
21
Q
what is an anion
A
some atoms are more stable with more electrons than protons
therefore ion carries a negative charge
22
Q
what is a cation
A
some atoms carry less electrons than protons
therefore ion carries a positive charge
23
Q
what is a radical
A
when a molecule has an unpaired electron
24
Q
what pH is acidic
A
1-7
25
what pH is neutral
7
26
What pH is alkaline
7-14
27
what are the 4 biomolecules
proteins
nucleic acids
carbohydrates
lipids
28
what are inorganic substances
water
| Ions (sodium, potassium, chloride, calcium, magnesium, bicarbonate, hydrogen phosphate)
29
what does a lysosome do
breakdown of proteins and other molecules
30
what does the nucleus do
contains DNA
31
what does RNA do
transcription & translation of proteins
32
What do ribosomes do
proteins production
33
what does the endoplasmic reticulum do
synthesis and storage
34
what does Golgi apparatus do
secretion of proteins
35
what does mitochondria do
site of metabolic processes
36
define metabolism
the sum of the chemical reactions occurring in a living organism/ part of it
37
what is the symbol for entropy
S
38
what does an increase in order do to entropy
decrease in entropy
39
what does a decrease in order do to entropy
increase in entropy
40
What is delta G
Free energy
41
What is the free energy equation
deltaG = DeltaH - TdeltaS
42
what is delta H
enthalpy (bond energy)
43
What is T delta S
Temp x entropy
44
what effects deltaG
Temperature
Pressure
Conc of reactants & products
pH
45
What are standard conditions for free energy change reaction
25 degrees
1atm pressure
pH 7
46
what is exergonic
free energy of products is lower than the reactants
therefore favoured
47
what is endergonic
free energy of products is higher than reactants
therefore unfavoured
48
What is equilibrium
dynamic state whereby energy of products and reactants is equal
49
When a compound accepts oxygen what happens
it is oxidised
50
When a compound loses oxygen what happens
it is reduced
51
When a compound loses hydrogen what happens
it is oxidised
| catabolism
52
When a compound accepts hydrogen what happens
it is reduced
| anabolism
53
how many hydroxyl groups do carbohydrates contain
at least 2 hydroxyl groups
54
what are monosaccharides
simplest carbohydrates
55
Function of carbs??
offer cells external protection (cellulose)
| assist cells in recognising molecules when attached to proteins and lipids
56
what are ogliosaccharides
when 2-10 monosaccharides link covalently
| linkages are glycosidic bonds
57
what is sucrose made from
glucose and fructose
58
what is lactose made from
galactose and glucose
59
what is maltose made from
2x alpha glucose
60
what are polysaccharides
formed from 10+ monosaccharides
61
give 2 examples of polysaccharides
cellulose
| starch
62
what do lipids exist as
exist as large tissue (adipose)
63
what is a common feature of lipids
low solubility in water
64
what is a saturated fat
single bonds only (palimate)
65
what is an unsaturated fat
single and double bonds
66
what are fatty acids linked by
ester bonds
67
role of vitamin B1
thiamine
| found in active site of pyruvate dehydrogenase
68
role of vitamin B6
coenzymes for aminotransferases and neurotransmitters
69
role of vitamin B12
serves as an enzyme in fatty acid processing
70
role of vitamin A
contained within the retinas of the eye
71
role of vitamin B2
riboflavin
| precursor of coenzymes for redox reactions
72
role of vitamin D
involved in calcium absorption - bone health
73
role of sodium
Main cation in extracellular fluids
Essential for electrical transmission in nerves and muscle
Maintains water content in various compartments of the body
74
role of calcium
critical component of bones and blood clotting
75
role of potassium
interacts with Na+ to maintain fluid balance and electrical impulses
76
role of magnesium
cofactor for hundreds of enzymes
77
role of iron
embedded in proteins handling oxygen and the electron transport chain
78
role of copper
is a cofactor for cytochrome, a key component in the electron transport chain
79
role of zinc
sits in the active site of around 200 enzymes, one of which helping get rid of co2
80
role of manganese
a cofactor for over 100 enzymes involved in metabolism
81
role of chloride
main anion of extracellular fluids. it interacts with Na in maintenance of fluid balance and electrical charges across cell membranes
used in production of HCL
82
role of phosphorus
phosphoryl groups covalently attached to vast array of biological compounds (nucleic acids, high energy phosphates)
83
what is transcription
DNA becoming mRNA
84
what is translation
mRNA becoming a protein
85
how many different types of protein in human body
74,000
86
what are the 3 parts to an amino acid
amino group
carboxyl group
side chain/ variable group
87
what gives an amino acid its identity
the side chain/ variable group
88
how are amino acids joined
covalently through peptide bonds
89
what is it called when multiple amino acids are joined together
a polypeptide chain
90
what is primary structure of a protein
the basic amino acid sequence that determines protein shape and function
The simplest structure
91
what is secondary structure of a protein
peptides fold in complex ways due to hydrogen bonds
| alpha helix & beta pleated sheet
92
what is tertiary structure of a protein
hydrogen bonds
electrostatic bonds
van der Waals interactions
disulphide bonds
93
what are electrostatic bonds between
positive and negatively charged groups
94
what are ionic bonds between
positive and negatively charged groups
95
what are van der Waals interactions between
a non covalent attraction due to movement of ions in atomic or molecular orbitals
96
what is quaternary structure of a protein
many proteins contain subunits that link together via the same interactions
97
what causes the denaturation of proteins
environmental factors such as heat/ acidity which can alter/ break forces
98
what are enzymes
essential catalysts that accelerate metabolic reactions
99
what are the 3 main features of enzymes
speed up reactions
display high specificity- each enzyme catalyses one reaction
catalytic power is regulated - speed of reaction is subject to a variety of factors
100
what are the limiting factors affecting rate of enzyme reactions
Substrate availability
Enzyme concentration
Temperature
pH
101
What are the purines
adenine & guanine
102
What are the pyrimidines
thymine (uracil in RNA)
| cytosine
103
what are nucleotides joined together by
phosphodiester bonds
104
is DNA double or single stranded
double helix
105
is RNA double or single stranded
single stranded
106
describe DNA replication
1. separate strands
DNA helices breaks H bonds to unzip molecule
2. primer binding
a small strip of RNA primer kickstarts replication
3. elongation
DNA polymerase adds complimentary base pairs in the 5- to 3- direction
4. termination
exonuclease removes original primers and then bases are re added to complete a new DNA double helix
107
what are the 3 types of RNA
mRNA (messenger, which decodes DNA)
rRNA (ribosomal, which decodes mRNA)
tRNA (transfer, which facilitates protein formation)
108
what are promotors
DNA region next to transcription site that docks RNA polymerase
109
what are enhancers
DNA regions that attract the transcription factor complex proteins
110
what is the trasncription factor complex
proteins that regulate the rate of mRNA formation
111
what are introns
non coding regions
112
what are exons
coding regions
113
describe translation
mRNA binds to subunit of rRNA where it is decoded
3 base sequence on mRNA is called a codon
this codon compliments an anticodon on a tRNA molecule
this binds to large subunit of mRNA holding an amino acid
allowing formation of a polypeptide chain via peptide bonds
ribosome moves along mRNA 5- to 3-
peptide bond formed between each amino acid
golgi apparatus modifies proteins & secreted in vesicles
114
describe how to measure total protein abundance via spectrophotometry
Bradford essay
protein mixed with blue dye called coomassie blue
in acidic conditions this results in a colour change brown-blue
115
what is the western blot
commonly used to detect a specific protein in a tissue homogenate or protein extract
116
what does Eliza testing stand for
enzyme linked immunosorbent assay
117
how does Eliza testing work
capture antibody and bind to well
add sample
wash microplate
add detection antibody
wash microplate
add substrate
read microplane
calculate results
118
is the myocyte single or multinucleated
multi nucleated due to fusion of myoblasts during development
119
can muscle fibres spontaneously contract
yes
120
what are the thick filaments called
myosin
121
what are thin filaments called
actin, tropomyosin, troponin
122
what is the m line made from
myosin and M protein
123
what is the Z line made from
a-actinin (alpha actinin)
124
what happens to the lengths of the filaments when the sarcomere contracts
they DO NOT change length
| but the OVERLAP INCREASES
125
How is contraction caused in the muscle
by thick myosin and thin actin filaments sliding over each other
126
describe myosin
very large & abundant in muscle
| consists of 2 large heavy chains & 2 small light chains
127
describe actin
main component of thin filaments
exists in 2 forms- G actin (globular) & F actin (fibrous)
tropomyosin and troponin attach to F actin
128
what happens to actin and myosin at rest
no binding
129
what part of myosin binds to actin
myosin head binds to actin
130
where on the the filament does myosin bind to actin
S1
causing a conformational change
creating a lever arm and power stroke happens generating force for contraction
131
what ion controls muscle contraction
calcium
132
how does calcium control muscle contraction
it permits the binding of myosin to F actin via troponin and tropomyosin
133
what is special about the acetylcholine receptor
it is ligand gated
134
what does ligand gated mean
it only changes its shape when interacting with its ligand (acetylcholine)
135
anabolic reactions can also be known as
endergonic
136
catabolic reactions are also known as
exergonic
137
what does myokinase do
add phosphate groups
138
is the myokinase reaction aerobic or anaerobic
anaerobic
139
what does creatine kinase (CK) do
can rapidly reform ATP
140
Are synthesis reactions anabolic or catabolic
anabolic eg- condensation
141
are breakdown reactions anabolic or catabolic
catabolic eg- hydrolysis
142
is glycolysis aerobic or anaerobic
anaerobic
143
what are the reactants of glycolysis
glucose
144
what are the products of glycolysis
2x pyruvate & NADH
145
how many ATP molecules are generated in glycolysis
2 atp molecules
146
what does exercise do to glycolysis and how
exercise speeds up glycolysis
1. substrate availability
2. physiological factors
3. cellular factors
4. molecular factors
147
what are the reactants of the Krebs cycle
acetyl coA
148
what are the products if the Krebs cycle
2 ATP
6 NADH
2 FADH2
8 H+
149
Is the Krebs cycle aerobic or anaerobic
aerobic pathway
150
where does the Krebs cycle take place
mitochondrial matrix
151
where does glycolysis take place
cytosol
152
What happens to Gibbs free energy when electrons are transferred
Gibbs free energy falls as electrons are transferred to FADH and NAD+ during glycolysis and Krebs cycle
153
what are reactants of oxidative phosphorylation
8 NADH
| 4 FADH2
154
what are products of oxidative phosphorylation
26 atp
6Co2
6H20
155
is oxidative phosphorylation aerobic or anaerobic
aerobic
156
what is gluconeogenesis
carbon skeletons from other molecules can be used to synthesise glucose for energy provision in a muscle
157
what helps digest protein in the stomach
pepsin enzyme
| Hydrochloric acid
158
how much of body % is protein in men
16%
159
how much of body % is protein in women
14%
160
how many of the 20 amino acids are glucogenic
14
161
how many of the 20 amino acids are ketogenic
2
162
how many of the 20 amino acids are glutogenic and ketogenic
4
163
is transamination reversible
yes
164
what is transamination
the transfer of one amino group from one molecule to another
catalysed by enzyme aminotransferase
165
what is deamination and what does it form
the amino acid removal and loss of its amino group
forms ammonia which is toxic (so gets converted into urea in liver and then excreted)
166
what does FSR stand for
fractional synthetic rate
167
what are lipids
Diverse biological compounds, characterised by low solubility in water
168
what makes up a phospholipid
glycerol & 2 fatty acids
169
what does amphipathic mean in relation to phospholipids
one end is hydrophobic
| one end is hydrophilic
170
what is a triacylglycerol made of
one glycerol unit
| 3 fatty acids
171
what are chylomicrons
```
a class of lipoprotein
transport of insoluble triacylglycerol
```
172
where does breakdown of triacylglycerol happen
in cytosol
173
where does synthesis of triacylglycerol happen
in cytosol
174
what is lipolysis affected by
epinephrine both increases and decreases lipolysis
| insulin reduces lipolysis
175
how are fatty acids degraded
through the pathway of beta oxidation in the mitochondria
176
how are lipids transported
in lipoproteins
177
what does exercise do to fatty acid oxidation
speeds it up
178
what is the energy yield of ATP-PC system
low
179
what is the energy yield of anaerobic system
medium
180
what is the energy yield of the aerobic system
high
181
what is the power of the ATP-PC system
High
182
what is the power of the anaerobic system
medium
183
what is the power of the aerobic system
low
184
how long does the ATP-PC system last
7 seconds
185
how long does the anaerobic system last
7-60s
186
how long does the aerobic system last
above 60s
187
is loosing electrons oxidation or reduction
oxidation
OILRIG
188
Is gaining electrons oxidation or reduction
redution
OILRIG
189
what Is the non specific part of the immune system called
innate immune system
190
what Is the specific part of the immune system called
acquired/ adaptive immune system
191
what is one of the main functions of the immune system
to be able to recognise self vs non self
192
what responses come under adaptive/ specific Immune system
```
cell mediated response (T cells)
Humoral response (B cells)
```
193
what responses come under innate/ non specific Immune system
```
blood borne (phagocytes)
Physical barriers (skin, saliva, yucas, stomach, tears)
```
194
what do T cells do
T cells release cytokine proteins which assist with killing infected cells
195
what do B cells do
can trigger release of antibodies
| can differentiate into plasma cells to produce antibodies
