bioe 1 Flashcards
(144 cards)
1
Q
ionic bonds
A
exchange of electrons from valence shell
atoms become ions
electrostatic force of attraction
high activation energy to break ionic bonds
2
Q
non-polarised covalent bonds
A
shared electrons
not ionic charge
weaker bond than ionic
3
Q
polarised covalent bonds
A
unequal sharing of electrons
usually atom with higher affinity for electrons being shared
one atom more electron dense so shared electrons spend more time circulating atom
partial delta positive and delta negative charges
4
Q
conservation of mass
A
mass neither created nor destroyed in chemical reactions
5
Q
synthesis
A
a + b -> ab
anabolic
endergonic
condensation
amino acids to proteins
6
Q
decomposition
A
ab-> a + b
catabolic
exergonic
hydrolysis
glycogen to glucose
7
Q
exchange
A
ab + c -> ac+ b
anabolic + catabolic
endergonic and exergonic
glucose + ATP
8
Q
condensation
A
anabolic process
yields water
e.g. two glucose molecules -> maltose
9
Q
hydrolysis
A
catabolic process
ATP hydrolysis essential for muscle contractions
hydrolysis of a dipeptide into two amino acids
10
Q
increase co2
A
dissolves in h2o
releases h+
creates carbonic acid
11
Q
increase h+
A
leads to acidosis (increase respiratory and pulmonary response to overcome)
eventually leads to fatigue
12
Q
metabolic acidosis
A
accumulation of metabolic acid
13
Q
salts
A
ionic bonds
structural components
electrolyte properties
dissociate in water
damaging in high conc
14
Q
acids and bases
A
covalent bonds
metabolic control
homeostasis (reversible)
dissociate in water
damaging in high conc
15
Q
acids
A
proton donors
dissociates in water
16
Q
hcl
A
in stomach for digestion
ph enzymes most efficient
17
Q
carbonic acid
A
weak acid
chemical buffering
18
Q
citric acid
A
second stage of carbohydrate breakdown
19
Q
strong acid
A
fully dissociates in water
irreversible
20
Q
weak acid
A
partial dissociation
reversible and conc driven
21
Q
bases
A
proton acceptor
dissociate in water
release oh-
22
Q
concentartion
A
molarity
moles per litre
23
Q
pH
A
quantitative measure of acidity or alkalinity of solution
ph = -log10 [h+]
distilled water [h+] = [oh-] pH = 7
human body pH average 7.4
24
Q
buffers
A
chemical and physiological mechanisms that moderate change in [h+]
increase [h+] = acidosis
decrease [h+] = alkolosis
25
physiological buffers
second line of defence
only occurs when change in ph is already occurred
renal buffering
ventilatory buffering
pulmonary ventilation
26
renal buffering
response time hours / days
regulate acidity through complex chemical reactions that restores bicarbonate into blood
secrete ammonia and h+ into urine
only pathway to eliminate acids other than carbonic acid
27
ventilatory buffering
faster response
changes the co2 conc
increase h+ stimulates ventilatory control
increase alveolar ventilation
increase co2 removal
27
ventilatory buffering
faster response
changes the co2 conc
increase h+ stimulates ventilatory control
increase alveolar ventilation
increase co2 removal
28
pulmonary ventilation
measures chemical state of blood in the medulla
variations in arterial
- partial pressure o2
- pp co2
- pH
- temp
adjust ventilation and maintain arterial blood chemistry
29
alkalosis and ventilation
decrease co2
due to hyperventilation (lots of breathing out so co2 forced out)
30
acidosis and ventilation
increase co2
due to hypoventilation (decrease ventilation)
not breathing out much co2 cause build up
31
pre exercise hyperventilation
causes alveolar co2 partial pressure to decrease
have a larger increase in co2 before needing to breathe
32
intense exercise on acid-base balance
increase [h+] from co2 production and lactate formation
large temp disturbance in acid-base balance
low pH cause nausea, headaches and dizziness
33
energy
the strength and vitality required for sustained physical or mental activity
34
thermodynamics law I
energy cannot be created nor destroyed but simply changed from one form to another
35
fuel
compound for which some of its chemical energy can be transformed into other forms when a chemical reaction takes place
triglycerides stored in adipose tissue
glucose used in brain
amino acids
36
glycogen
stored in liver and muscle
stored with water
1g glycogen with about 3g water
37
triacylglycerol
stored in adipose tissue
huge range in body fat from 2% to 70%
38
thermodynamics law II
all potential energy in a system degrades to unusable form of kinetic or heat energy
process of change reflects entropy
39
mechanical work
muscle contraction
convert chemical to mechanical energy
energy supports myosin head crossbridge formation
40
chemical work
maintenance and growth
muscle tissue synthesis in response to chronic overload in training
41
transport work
high -> low conc in diffusion = no energy
low -> high conc in active transport = energy
na+/ k+ -> atpase
42
Kcal
amount energy to increase temp of 1kg water by 1 degrees
1Kcal = 4.184 kj
43
joule
is the energy expended when 1 newton moves a distance of 1m
44
measurement of food energy
bomb calorimeters measures gross energy value of macronutrients
direct calorimetry measures heat liberated as food burns
heat of combustion is total energy value of the food
45
gross and net energy in food
gross energy from bomb calorimetry not the same as net energy due to protein
body cannot oxidize nitrogen component of protein
nitrogen combines with hydrogen to form urea and excreted from kidneys as urine
elimination of hydrogen in manner represents loss of approx 19% of proteins potential energy
46
coefficient of digestibility
ability of body's digestive processes to extract potential energy
47
Atwater general factors
energy from food is corrected for loses in digestion, absorption and urinary excretion of urea
much less than calculated in a bomb calorimeter and what is available for fuel from what we digest
4Kcal / g dietary carbohydrates
4Kcal/ g dietary protein
9 Kcal / g dietary lipid
7 Kcal / g dietary alcohol
48
enzymes
specific protein catalyst that accelerates forward and reverses rates of chemical reactions without being consumed or changed
lowers the activation energy
49
lock and key theory
substrate matches active site of enzyme
enzyme-substrate complex splits to yield product
50
induced fit theory
in presence of substrate induces the active site of the enzyme to change shape slightly
key for delayed action needed for enzymes
51
allosteric enzymes
can be positively and negatively effected
have separate allosteric sites
52
positive effector allosteric enzyme
increases enzyme activity
less time to Km
53
negative effector allosteric enzyme
reduces enzyme activity
54
impact pH on enzyme
extreme pH denatures enzyme and changes struct
smaller changes modify behaviour
55
effect of temp on enzyme
increase temp increases rate of reaction
thermal denature occurs >50 and reaction rate falls
optimal range for humans 30-40
56
homeostasis
ability of body or cell to seek and maintain condition of equilibrium or stability within its internal environment when dealing with external chnages
57
positive feedback loop
expands initial stimulus response towards change direction
58
cell membrane
primary function is barrier
regulates rate of transport into the cell
provides surface for attachment proteins
phospholipid bilayer
- hydrophilic head
- hydrophobic tails
- fluidity
59
passive transport
simple diffusion
facilitated diffusion
osmosis
filtration
60
simple diffusion
passive movement of molecules from higher to lower conc
water molecules, o2, co2, small uncharged, lipid soluble molecules
61
facilitated diffusion
transport of substances across a membrane from area higher to lower conc by means of carrier molecule
can be voltage dependent
can be open or shut
62
osmosis
movement of water from higher water potential to a lower water potential
63
isotonic solution osmosis
no net movement water
64
hypotonic solution osmosis
water moves into cell
water potential of solution higher
may cause cell to burst if wall weak or damaged (osmotic lysis)
65
hypertonic solution osmosis
water moves out of the cell
water potential of solution lower
causes cytoplasm to shrink (plasmolysis)
66
filtration
movement of water and solutes across membrane due to hydrostatic pressure from cardiovascular system
e.g. nephron in the kidney
filters out water, ions, drugs and urea
higher blood pressure = higher filtration
67
active transport
bulk transport
- endocytosis
- exocytosis
- phagocytosis
primary active transport
secondary active transport
68
primary active transport
use of ATP to provide energy for movement against conc gradient
Na+/K+ pump most common
takes Na+ out and K+ into the cell against conc gardient
important to maintain resting membrane potential
69
secondary active transport
ion conc gradient created by primary active transport helps to move another substance into the cell
either symporter or antiporter
70
symporter
movement same direction to ion
71
antiporter
movement opposite direction to ion
72
bomb calorimetry
burn something in oxygen atmosphere
measure temp change of water due to combustion and determine how much energy released
73
steps of bomb calorimetry
1. weigh the sample
2. place sample in bomb
3. pressurise the bomb with oxygen
4. place the water in calorimeter
5. calorimeter into insulated bucket and bomb connected to electrodes and then fully submerged in the water
6. leave for about five mins until steady temp reached
7. fire
8.watch temp change and record every 30 secs until steady
74
ATP
composed of adenine, ribose and phosphate
energy release when phosphate bond is broken
exergonic reaction and hydrolysis
cannot be accumulated or transferred from cell to cell
cells die if no more ATP generated
maintenance of ATP/ADP conc ratio in cells usually takes precedence over cell function
50:1
75
ATP:ADP ratio
50:1
76
energy released by hydrolysis of ATP
liberated for muscle contraction
7.3 Kcal per mol
catalysed by ATPase or adenosine triphosphatase
77
ATP formation from ADP
2ADP ->ATP + AMP
catalysed by adenylate kinase
more energy in one ATP than two ADPs
78
ATP splitting
ATP hydrolysis doesn't require oxygen
energy rapidly available
transport of atmospheric 02 to cites of requirement is long process so would impair immediate energy source
79
ATP storage and use
ATP heavy compound so limited stored at a time
80-100g of ATP at any time
at exhaustion not ran out of ATP
rapid re synthesis essential to allow normal functioning
replenishment sites present in mitochondria (aerobic) and cystol (anaerobic)
80
PCr
instant replenishment of ATP achieved by high energy phosphate phosphocreatine
mediated by creatine kinase enzyme
cells store about 18 mmol per kg of muscle
PCr theoretically depleted within about 8-12 secs
provides energy 'buffer' while longer term energy pathways 'getting going'
81
mass
amount of matter in an object (g/kg)
82
weight
product of mass and gravity on earth (N)
1kg = 9.81 N
83
density
mass per unit of material substance
mass / vol g/cm^3
84
molecules
two atoms of the same element
85
compound
two atoms of different elements
86
free radicals
charged atoms or group with unpaired electron in outmost shell
highly reactive
unstable
87
enthalpy change (∆H )
change in energy of the reactants when turned into products
measured as total heat energy change
negative delta H = exergonic
positive delta H = endergonic
88
entropy change (∆s)
measure of energy dispersal
energy wants to spread from conc to spread out
feasible when delta s > 0
89
free energy change (∆G)
max energy available from reaction that can be harnessed to be useful
energy released ∆G<0 and exergonic reaction
∆G>0 not feasible
∆G = ∆H-T∆s
90
enzymes in redox reactions
dehydrogenases (removal of H)
oxidases (removal of O)
91
coenzymes
less specific than enzymes
temporary carriers
reversible electron and hydrogen acceptors
NAD+
FAD
some created in liver
92
transamination
transfer of amino group from an amino acid to an alpha-ketoacid in presence of a transaminase
important for production of non-essential amino acids
often include use of glutamate
93
deamination
removal of ammonia group
amino acid forms alpha keto-acid and ammonia
94
glutamine synthesis
from glutamate
has 2 nitrogens
gluconeogenic precursor -> enables net synthesis of glucose
95
nitrogen excretion
catabolic (breaking down)
removes nitrogen via ammonia in purine nucleotide cycle
ammonia is toxic
ammonia -> urea -> urine -> excreted
96
proteins
contain amino acids
joined by peptide bonds
peptides 2-10 amino acids
every protein has function
no storage
97
functions of proteins
enzymes
cell membrane transporters and receptors
transport and signal
structure of cell, muscle, bones and connective tissue
regulatory function: immune system and hormones
98
primary struct proteins
how amino acids are linked
the amino acid sequence
99
secondary struct proteins
backbone torsion angles in amino acid residues due to hydrogen bonds
100
tertiary struct proteins
coordinates of all the atoms in the protein
101
quaternary struct proteins
position and orientation of all proteins in a complex
102
causes changes in protein struct
temperature
pH
enzymatic action
103
temp changing protein struct
increase kinetic energy breaks hydrogen bonds denaturing proteins
104
pH changing protein struct
causes ionic and hydrogen bonds to break
105
enzymatic action changing protein struct
remove unwanted and ineffective part of amino acid chain
106
non essential amino acids
can be made in the body
107
essential amino acids
need to be taken in via diet
108
extraction of energy from glucose through
glycolysis
TCA cycle
oxidative phosphorylation
109
glycolysis
start product glucose or glycogen
takes place in cytoplasm
aerobic glycolysis -> pyruvate
anaerobic glycolysis -> lactate
requires glucose, enzymes, NAD+, ATP , ADP
produces pyruvate, NADH, ATP
110
lactate
produced all the time
rate of glycolysis faster than subsequent stages of CHO metabolism
high metabolic rate NADH high and NAD+ low
favours conversion of pyruvate to lactate
NAD+ produced helps maintain glycolytic rate
111
beta oxidation
occurs in mitochondria
2c fragments removed from carboxyl end of fatty acid
rate limiting enzymes
112
lipoprotein lipase
breaks down TAG to take it up into tissue
113
hormone sensitive lipase
breaks down TAG within tissue
114
adipose tissue
not h2o soluble
break down TAG ->glycerol -> gluconeogenesis process -> glucose
fatty acids -> ketogenesis -> ketones
115
endogenous
in the body
116
exogenous
external from the body from food digested
117
adipose tissue
TAG - main storage form
9Kcal per gram
5Kg adipose same as 31Kg glycogen
specialist tissue
unlimited storage
118
mobilisation of stored TAG and oxidation of FFA
1. release of FFA from TAG
2. alpha- oxidation of FFA (branched chain FFA only)
3. beta- oxidation of FFA -> TCA cycle + ETC ->ATP
119
release FFA from TAG
1. lipolysis
2. fate of glycerol
3. fate of FFA
120
lipolysis
hormone sensitive lipase
triglyceride lipase -> removes 1st fatty acid
diglyceride lipase -> remove 2nd fatty acid
monoglyceride lipase -> remove 3rd
creates 3 FFA + glycerol
121
fate of glycerol
not used in adipose
glycerol phosphate
dihydroxyacetone phosphate
glucose glyceraldehyde
122
fate of FFA
FFA move out and bind to Albumin
carried to tissues
transport across membrane by fatty acid binging proteins
branched chain FFA undergo alpha oxidation
coA derivatives
123
phospholipids
component of cell membrane
a diglyceride (2 fatty acids)
hydrophobic fatty acid
hydrophilic phosphate
124
function of lipids
maintain functional and structural integrity of cell membrane
surfactant - reduce surface tension from breathing and prevent lungs from collapsing
provide insulation and protection to organs
hormone and neurotransmitter action
125
sterols
found naturally in foods
compound with multiple ring structure
synthesis of steroid hormones and vitamin D
126
FFA
free fatty acids
even numbers of carbons (4-28)
carboxyl group and methyl group either end
hydrogen, carbon and oxygen
classification by no carbons, double bonds and location of first double bond
127
no of carbons FFA
short chain -> less than 8
medium chain -> 8-14
long chain -> 16-28
128
cis- fat molecule
hydrogens on same side of double bond
found in nature
129
trans- fat molecule
hydrogens on opposite side of double bond
milk and butter
130
hydrogenation
removes double bond
protects from oxidation
texture
polyunsaturated act like saturated
131
triglycerides (TAG)
1 glycerol and 3 fatty acids
95% of all dietary lipids
storage in form of adipose tissue
9 Kcal per gram
1kg = 7000 Kcal
132
role and function of triglycerides
energy -> muscle contraction
insulation -> TAG is a poor conductor
protection -> vital organs
spare other fuels -> carbs sparing
133
carbohydrate
carbon, hydrogen and oxygen
monosaccharide, disaccharide and polysaccharide
carbonyl group (CHO)
glycosidic bonds
134
blood glucose
normal conc 3-5 mmol/L (euglycemia)
regulated by hormones
primary cerebral fuel
135
glucogenesis
formation of glycogen from sugar molecules
136
gluconeogenesis
formation of glycogen from amino acids, fats and other noncarbohydrates
137
glycogenolysis
breakdown of glycogen into glucose
catalysed by enzyme glycogen phosphorylase
138
how to generate ATP
PCr
glycolysis
oxidative phosphorylation
139
PCr in generating ATP
low capacity
max rate achieved in seconds
140
glycolysis in generating ATP
intermediate capacity
intermediate rate
141
oxidative phosphorylation in generating ATP
high capacity
low rate, max rate achieved in 1-3 mins
142
ATP synthesis in cystol
glycolysis
PCr hydrolysis
143
ATP synthesis in mitochondrion
TCA cycle, oxidative phosphorylation and beta- oxidation
