Exam Revision Flashcards
1
Q
What are the 3 secondary structures?
A
Alpha helix
Beta sheet
Beta bend
2
Q
What is the charge of acidic side chains?
A
Negative
3
Q
What is the backbone of DNA called?
A
Deoxyribose-phosphate backbone
4
Q
What joins amino acids together?
A
Peptide bonds
5
Q
What are the different protein structures?
A
Primary
Secondary
Tertiary
Quarternary
6
Q
What is the process of forming glycoproteins called?
A
Glycosylation
7
Q
What is collagen composed of?
A
(glycine - x - proline)n
Where x can be:
Alanine
Hydroxyproline
Lysine
8
Q
What percentage of body weight does water make up?
A
60%
9
Q
What is the cytoskeleton made of?
A
Microfilaments
Intermediate filament
Microtubules
10
Q
Whare are microfilaments made of?
A
Actin
11
Q
What are intermediate filaments made of?
A
Fibrous proteins
12
Q
What are microtubules made of?
A
Tubulin
13
Q
What is the difference between trans and cis?
A
Cis is symettrical
14
Q
What is the KW of water?
A
1 x 1014 mol/L
15
Q
What are examples of important buffers?
A
Bicarbonate
Phosphate
16
Q
How much Na and K does each molecule of ATP allow through the pump?
A
3 Na
2K
17
Q
What is the osmolarity of the plasma?
A
385 mOsmols/L
18
Q
What is the difference between the absolute refractory period and the relative refractory period?
A
Absolute is when all gates are opened and excitability is low
Relative is when gates are closed and excitability is increasing
19
Q
What are examples of alpha, beta and C waves?
A
Alpha - proprioception, touch, fast pain
Beta - preganglionic autonomic fibres
C - heat, slow pain
20
Q
What is acetylcholine removed from the NMJ by?
A
Acetylcholinesterase
21
Q
What is the cofactor?
A
Non protein component needed for activity
22
Q
What is the co enzyme?
A
Complex organic molecule usually produced from a vitamin
23
Q
What is FAD derived from?
A
Riboflavin
24
Q
What is NAD derived from?
A
Niacin
25
What is the prosthetic group?
Cofactor covalently bound to enzyme
26
What is the apoenzyme?
Protein component of enzyme that contains a cofactor
27
What is the difference between lyases and ligases?
Lygases form or add to double bonds
Liases form C-C, C-S, C-O or C-N bonds
28
Where is hexokinase and glucokinase found?
Glucokinase - liver
Hexokinase - everywhere else
29
What is KM and what does it indicate?
Concentration of the substrate at half the max v
High KM indicates a low affinity
30
What do the X and Y intersections on a Lineweaver-Burk plot represent?
Y - 1/vmax
X - 1/KM
31
What can you say about the first and second steps on an enzyme controlled reaction?
First is reversible
Second is rate limiting
32
What is an example of an enzyme that uses a sequential mechanism?
Lactate dehydrogenase (pyruvate to lactate)
33
What is an example of an enzyme that uses a random sequential mechanism?
Creatine kinase (creatine to phosphokinase)
34
What is an example of an enzyme that uses no ternary complex formation?
Asparate aminotransferases
35
What is used to show enzyme mechanisms?
Cleland notation
36
What is connective tissue composed of?
Ground substance
Collagen
Elastin
37
What is the ground substance composed of?
Glycoproteins and carbs
38
Where are desmosome junctions found?
Cardiac muscle
Bladder
39
Where are tight junctions found?
Intestine and stomach
40
Where are gap junctions found?
Cardial and neurons
41
What is the basement membrane composed of?
Basal lamina
Reticular lamina
42
What is the basal lamina?
Secreted by epithelial cells which they sit on
43
What is the reticular lamina?
Connects basal lamina to underlying connective tissue
44
What are the 2 kinds of glands?
Exocrine
Endocrine
45
What do exocrine glands do?
Secrete into tubes
46
What do endocrine glands do?
Secrete into the blood
47
What are the 2 kinds of ducts from exocrine glands?
Simple (unbranched)
Compound (branched)
48
What are the 2 kinds of excretory components of exocrine glands?
Tubular
Accinar
49
What are the 3 kinds of secretion from a gland?
Merocrine
Apocrine
Halocrine
50
What is merocrine?
Exocytosis
51
What is apocrine?
Discharge vesicles
Example is sweat glands
52
What is halocrine?
Discharge whole cell
Example is sebaceous gland
53
What cells produce the secretions within glands?
Myoepithelial cells once they contract
54
What is the thyroid gland special?
Contains follicles of hormones (thyroxine) which is reabsorbed before being released into the blood
55
What is a single celled gland?
Goblet gland
56
What are examples of exocrine organs?
Liver
Major silival gland
57
What are examples of endocrine organs?
Thyroid
Adrenal
58
What is the pancreas an example of?
An endocrine and exocrine organ
59
What is an example of loose connective tissue?
Adipose
60
What are the 3 components of connective tissue?
Fibres
Tissue fluid
Ground substance
61
What are examples of different collagens and where are they found?
Type I in tendons
Type III in reticular lamina
Type IV in basil lamina
62
What is collagen and elastin secreted by?
Connective tissue
63
What does loose connective tissue do?
Attach epithelial to underlying tissue
64
What are 4 cells permanent cells in loose connective tissue?
FIbroblasts
Macrophages
Adipocytes
Mast cells
65
What is an example of a dense regular connective tissue?
Tendons
66
What is an example of a dense irregular connective tissue?
Subacceous gland
67
What are some proteins usually coupled to G proteins?
Adrenylyl cyclase
Phospholipase C
68
Where is Ca stored?
Endoplasmic reticulum
69
What is EC50?
Concentration of a drug to produce half the maximum effect
70
What are fibrous joints made of?
Dense fibrous connective tissue
71
What are the 4 basic cells in the epidermis?
Dendritic cells
Karatinocytes
Melanocytes
Merket cells
72
What are merkel cells?
Touch receptors
73
What are the 5 layers of the epidermis?
Stratum basule
Stratum spinosum
Statum glanulosum
Stratum lucadum
Stratum corneum
74
What happens in the stratum basule?
Continuous proliferation
75
What happens in the stratum spinosum?
Cells shrink
Desmosome junctions create 'spikes'
76
What is in the statum granulosum?
Granules of keratohyaline
77
What happens in the stratum lucadum?
Conversion of keratohyaline to keratine
78
What is unique about the statum corneum?
No organelles
79
Where are melanocytes and merkel cells?
Stratum basule
80
What binds cells of the stratum basule to the basement membrane?
Hemidesmosomes
81
What gives strength to the stratum lucidum?
Disulphide bridges
82
What are the 2 layers of the dermis?
Papillary layer
Reticular layer
83
What is the papillary layer?
Loose connective tissue that protects against pathogens
84
What is the reticular layer?
Dense irregular connective tissue that attaches the skin to underlying tissues
85
What is found in the papilary layer?
Macrophages
Blood vessels
Nerve endings
86
What is unique about the subbaceous gland?
Only gland to secrete directly into the hair follicle
87
What are the 3 important hexoses?
Glucose
Fructose
Galactose
88
What are disaccharides linked by?
Glycosidic bonds
89
What is the only carbon that can be oxidised?
Anomeric carbon
90
What are 3 important dissacharides?
Maltose
Lactose
Succrose
91
What is maltose formed from?
Glucose and glucose
92
What is lactose formed from?
Glucose and galactose
93
What is succrose formed from?
Glucose and fructose
94
What are the 2 glucose monomers in starch?
Amylase (alpha 1-4)
Amylopectin (alpha 1-4 and alpha 1-6)
95
What are glycoaminoglycans?
Unbranched polymers made from repeating units of hexuronic acid and an amino sugar
96
What is a property of glycaaminoglycans and where are they found?
Sticky and slimy, found in synovial fluid
97
What is a proteoglycan?
Formed from GAGs and proteins, more carbs than protein
98
What are mucopolysaccharides?
Genetic disorders caused by absence of the enzyme that breaks down glucoaminoglycans (GAGs)
99
Where are carbohydrates digested?
Mouth
Jejanum
Duodenum
100
What enzyme acts on carbohydrates in the mouth?
Silivary amylase which breaks down alpha 1-4
101
What is the breakdown of carbohydrates like in the duodenum?
Similar to the mouth
102
What are some enzymes that break down carbohydrates in the jejunum?
Isomaltose (hydrolyses alpha 1-6)
Glucamylase (removes glucose from non reducing end)
Sucrase (hydrolysis succrose)
Lactase (hydrolysis lactase)
103
How is glucose absorbed?
Driven by Na pump:
1) Taken into gut epithelium by glucose transporter (2Na and 1 glucose in)
2) Passes down concentration gradient into the blood
104
What can you say about cellulose and hemicellulose?
Cannot be digested so are broken down by gut bacteria, producing methane and hydrogen (smelly farts)
105
What is glucose immediately changed into in the liver and why?
Glucose-6-phosphate so it doesnt leave the cell
106
What is the reaction of glucose to glucose-6-phosphate controlled by?
Glucokinase in the liver
Hexokinase everywhere else
107
What controls the reaction of glucose-6-phosphate to glucose?
Glucose-6-phosphatase
108
What is the process of the synthesis of glycogen?
1) Glycogenin covalently binds glucose from uracil diphosphate (UDP) glucose to form a chain of about 8 monomers
2) Glycogen synthase extends the chain
3) Glycogen branching enzymes break chain and reattach alpha 1-6
4) Glycogen synthase takes over again
109
What is the process of the degradation of glycogen?
1) Glucose monomers removed 1 at a time from non reducing end by glycogen phosphorylase to produce G-1-P
2) Branch removed by debranching enzyme
a) Transferase removes 3 glucose monomers and attaches them to nearest non-reducing end by alpha 1-4 bond
b) Glucosidase removes final glucose monomer by breaking alpha 1-6 and releasing a free glucose
3) Process repeats
110
What are the 2 phases of glycolysis?
Preparative phase (2 molecules of G-3-P produced from G-6-P, using 2 ATP)
Payoff phase (1 molecule of pyruvate made per G-3-P, making 4 ATP)
111
What are the 3 steps of glycolysis that are irreversible?
Step 1 (glucose to glucose-6-phosphate)
Step 3 (F-6-P to F-1,6,bisP)
Step 10 (transfer of P from PEP to ADP, producing pyruvate)
112
What is the first commited step of glycolysis?
Step 3 (F-6-P to F-1, 6bisP)
113
What do all fates of glycolysis regenerate?
NAD
114
What enzyme controls the reation of pyruvate to lactate?
Lactate dehydrogenase
115
What happens to lactate at the end of the cori cycle?
Transfered to liver and convered to pyruvate for gluconeogenesis
116
Where does glycolysis happen?
Cytoplasm
117
Where does the reaction pyruvate to acetyl coA happen?
Mitochondria
118
Where is the enzyme that controls pyruvate to acetyl coA?
Pyruvate dehydrogenase
119
What are tissues that completely rely on glycolysis?
Brain
Nervous tissue
RBCs
Testis
Embryonic tissue
120
What is the reaction gluconeogenesis uses to bypass step 10 of glycolysis?
1) Pyruvate to oxaloacetate (controled by pyruvate carboxylase)
2) Oxaloacetate to PEP (controlled by PEP carboxylase)
121
Where is G-6-P converted into glucose?
Endoplasmic reticulum (G-6-P shuttled in and glucose and Pi shuttled out)
122
What enzyme controls F-1,6-bisP to F-6-P?
Fructose-1,6-biphosphotase
123
Where can fructose enter glycolysis?
Liver (dihydroxyacetone phosphate (DHAP) or glyceraldehyde - phosphate (GAP))
Adipose tissue (F-6-P)
124
Where can galactose enter glycolysis?
G-6-P
125
What does the pentose phosphate pathway produce?
Pentose
NADPH
126
What are the 2 stages of the pentose phosphate pathway?
1) Oxidation (irreversible)
2) Non oxidation (reversible)
127
What happens in the oxidation stage of the pentose phosphate pathway?
1) Generates NADPH
2) Converts G-6-P to pentose phosphate
128
What happens in the non oxidative stage of the pentose phospahte pathway?
Produces lots of 3, 4, 5, 6, 7 carbon sugars
129
What does breaking ethanol down require?
NAD
130
What do low levels of NAD lead to?
Increased blood lactate
Decrease blood glucose
131
What is vitamin C?
Monosaccharide
132
Where does the CIC happen?
Mitochondrial matrix
133
What does the CAC do?
Removes electrons from intermediates and passes them onto NAD and FAD
Each time 2C enters (acetly coA) and 2C leaves
134
What is pyruvate dehydrogenase inhibited by?
Acetyl coA
ATP
NADH
135
What is pyruvate dehydrogenase activated by?
Pyruvate
ADP
136
What are the enzymes that control the 2 irreversible steps in the CAC?
Isocitrate dehydrogenase
a-ketoglutamate dehydrogenase
137
Which of NADH and FADH2 cannot cross the mitochondrial membrane?
NADH cannot
138
How does NADH in the cytoplasm pass its electrons into the electron transport chain?
Glycerol phosphate shuttle
139
What is the process of the glycerol phosphate shuttle?
1) NADH passes electrons onto dihydroxyacetone phosphate which becomes glycerol-3-phosphate
2) Crosses outer membrane and passes electrons onto FAD which becomes FADH2
3) Enters electron transport chain
140
How many proteins are in the electron transport chain?
4
NADH-Q Oxidoreductase
Succinate-Q Reductase
Q-Cytochrome C Oxidoreductase
Cytochrome C Oxidases
141
What does the first protein of the ETC do?
Oxidise NADH and pass electons onto ubiquinone which becomes ubiquinol
Pumps H+ into intermembrane space
Uses Fe-S centres
142
What does the second protein of the ETC do?
Oxidises FADH2 and passes its electrons onto ubiquinone which becomes ubiquinol
Fe-S centres
Haem group captures stray electrons
143
What does the third protein of the ETC do?
Transfers electrons from ubiquinol to cytochrome C
Pumps protons into intermembrane space
144
How much cytochrome C does 1 ubiquinol make?
2 molecules
145
What does the fourth protein of the ETC do?
Passes electrons from cytochrome C to O2
Pumps protons into intermembrane space
Fe-Cu centres
146
What proteins of the ETC pump protons?
1, 3 and 4
147
What are the 2 parts of ATPsynthase?
F0 (membrane bound protein)
F1 (protrudes into mitochondrial matrix)
148
How many subunits does F0 have?
10
149
What is the process of ATPsynthase?
1) ADP and Pi enter beta subunit of F1
2) Rotation of F0 and gamma shaft causes conformation change in beta subunit
3) Catalysis ADP and Pi to ATP
150
When does ATPsynthase rotate?
When 3 H+ enters
151
How much H+ is needed to generate 1 molecule of ATP?
3
152
How much ATP does NADH and FADH2 generate
NADH generates 2.5 per molecule
FADH2 generates 1.5 per molecule
153
What does uncoupling of the ETC cause?
Generation of heat instead of energy, as seen in brown fat
154
What are the 5 classes of lipids?
Fatty acids
Triacyglycerols
Phospholipids
Glycolipids
Steroids
155
What is an example of lipid naming?
18:3 (9, 12, 15)
18 carbon long, 3 double bonds after carbon 9, 12 and 15
156
Why can essential fatty acids not be synthesised?
We cannot intoduce double carbon bonds after carbon 9
157
What is omega 3 derived from?
Linolenic acid
158
What is digestion of lipids by pancreatic enzymes (lipases) promoted by?
Emulsufication by bile salts and peristalsis
159
What are bile salts a derivitive of?
Cholesterol
160
What is triacyglycerol degraded to in the small intestine?
2 fatty acids and a monoacylglycerol
161
What is cholesterol digested into?
Cholesterol and a fatty acid
162
What are phospholipids digested into?
Lysophospholid and a fatty acid
163
What is the process of digesting lipids?
1) Fats become emulsified in duodenum due to bile
2) roken down into fatty acids and glycerol in small intestine
164
What is the uptake of digested lipids in the small intestine?
1) Forms micelles with bile salt, which releases the lipids near the membrane which diffuse accross
Short and medium chain fatty acids do not need micelles
165
What happens to lipids that have been absorbed in the small intestine?
1) Resynthesised by intestinal epithelium cells for export
2) Packaged with apoB-48 into chylomicrons
3) Released by exocytosis into the lymph and then the blood
166
What happens to chylomicrons once they reach tissue?
1) Hydrolysid to fatty acid and glycerol by lipoprotein lipase
2) Used for energy or reesterfication to triacyglycerol for storage
167
What happens to chylomicron renmants?
Go to the liver where glycerol is used to produce glycerol-3-phosphate
168
What causes fatty acid to be released from adipose tissue?
Hormone sensitive lipase being activated by noradrenaline
169
What is hormone sensitive lipase deactivated by?
High plasma glucose
Insulin
170
What are examples of lipoproteins that carry lipids in the blood?
Chylomicron
VLDL
LDL
HDL
171
What is VLDL do?
Transfers tracyglycerol from liver to tissue
172
What does beta oxidation produce?
Acetyl coA
FADH2
NADH
173
Where does beta oxidation occur?
Mitochondrial matrix
174
What are the 3 stages of beta oxidation?
1) Activation of fatty acid in cytosol
2) Transport into mitochondria
3) Degradation to acetyl coA
175
What do fatty acids form when they are activated and what enzyme controls this?
Fatty acid and acetly co A becomes fatty acyl coA (enzyme is acyl coA synthase)
176
What does fatty acid use to enter the mitochonrial matrix?
Carnitine shuttle
177
What is the process of the carnitine shuttle?
1) Carnitine reacts with fatty acyl coA to produce acyl carnitine which crosses membrane
2) Acyl carnitine reacts with coA to produce fatty acyl coA
3) Carnitine returns to cytosol
178
What are the enzymes used in the carnitine shuttle?
Carnitine palmityl transferase I and II
179
What inhibits carnitine palmityl transferase?
Malonyl
180
What does not need to use the carnitine shuttle?
Short and medium chain fatty acids
181
What does each stage of beta oxidation produce?
1 acetyl coA
Carbon species 2 shorter
1 NADH
1 FADH2
182
What is the net yield of ATP for beta oxidation?
129 molecules
183
What happens when you are starving?
1) Liver flooded with acetyl coA
2) Inhibits pyruvate dehydrogenase and activates pyruvate carboxylase (pyruvate to oxaloacetate)
3) Produces glucose through gluconeogenesis
184
What is excess acetyl coA converted into?
Ketones
185
Where are ketones made?
Mitochondrial matrix of liver
186
What cannot use ketones for energy?
Liver
187
What cannot use fatty acids for energy?
Brain
188
Where does fatty acid synthesis occur?
Cytosol
189
How does acetyl coA get to the cytosol for fatty acid synthesis?
Citrate shuttle
190
What is the process of the citrate shuttle?
1) Acetyl coA reacts with oxaloacetate to become citrate which crosses the membrane
2) Citrate broken down to acetyl coA and oxaloacetate in cytosol
3) Oxaloacetate uses NADH to become malate
4) Malate uses NAD to become pyruvate to cross into matrix
5) Pyruvate converted to oxaloacetate
191
What is produed in the citrate shuttle?
NADPH which is used later for fatty acid synthesis
192
What is the product of fatty acid synthesis?
Palmitic acid
193
What is the rate determining step in fatty acid synthesis?
Acetyl coA and ATP to melonyl coA (catalysed by acetyl coA carboxylase)
194
What is acetyl coA carboxylase activated and inhibited by?
Activated by insulin
Inhibited by palmitoyl coA, glucagon and noradrenaline
195
How much NADPH does the formation of palmitic acid uses and where does it come from?
14 from citrate shuttle and pentose phosphate pathway
196
What are some specialised lipid classes?
Steroid hormones
Cholesterol
Eicosanoids
197
What is cholesterol used to make?
Steroid hormones and membranes
198
What are eicosanoids derived from?
Omega 3 and omega 6
199
What does nitrogen to other molecule flow through?
Glutamate
200
What is transanimation?
Transfering amino groups through different molecules
201
What do all amino transfers rely on?
Pyridoxal phosphate cofactor (transfers amino group, derived from vitamin B6)
202
What is the proces of dietry proteins being broken down?
1) Pepsin cuts proteins into peptides in the stomach
2) Trypsin and chymotrypin cut proteins and large peptides into smaller peptides in the small intestine
3) Aminopeptidases and carboxypipdases A and B degrade peptides into amino acids in small intestine
203
What tages cellular proteins that are to be degraded?
Ubiquione
204
What are the fates of amino acids?
Left in tack for biosynthesis
Broken down into carbon skeleton and amino group
205
What is the fate of an amino group from a broken down protein?
Nitrogen disposed by urea cycle
206
What are the possible fates of carbon skeletons?
Glucose or glycogen synthesis
Cellular respiration
Fatty acid synthesis
207
What is amonia transported through the bloodstream as?
Glutamine
208
What is pyruvate converted into once it donates it accepts an amino group?
Alanine
209
What is the pyruvate - alanine cycle?
1) Protein broken down in exercise if required
2) Transported to liver as alanine
3) Carbon skeleton converted to pyruvate
4) Nitrogen excreted as ammonia in urine
5) Pyruvate to oxaloacetate to glucose (gluconeogensis)
210
What are the 2 nitrogen acquiring reactions of glutamate being broken down in the liver?
1) Synthesis of carbamoyl phosphate
2) Entry of asparate into urea cycle
211
How many amino acids are essential?
8
212
What are the 2 kinds of carbon skeletons?
Glucogenic (feeds into gluconeogenesis)
Ketogenic (feeds into CAC)
213
Where does the urea cycle happen?
Split between mitochondrial matrix and cytosol
214
What goes in and out of the urea cycle?
Ammonia goes in and urea comes out
215
How many enzymes are involved in the urea cycle?
6 enzymes
216
What is the most common urea cycle defect?
UTC difficiency (X linked)
217
What is PKU?
Absence/difficiency of phenylalanine hydroxylase, causing a build up of phenylalanine levels which is toxic
218
What receptors does the autonomic and somatic nervous systems use?
Somatic uses iatotropic
Autonomic uses metatropic (G proteins)
219
What kinds of receptors does acetylcholine act on?
Cholinergenic:
Nicotinic (2)
Muscarinic (3)
220
What receptors does noradrenaline act on?
Adrenic:
Alpha (2)
Beta (3)
221
How does the adrenal medulla work?
Sympathetic fibres innervate it and cause it to release adrenaline and noradrenaline into the blood
222
What are examples of post ganglionic fibres not following the rules?
Sympathetic cholinergic fibres innervate sweat glands
Some release neurotransmitters like peptides or NO
223
What is an example of antagonistic innervation of the autonomic nervous system?
Eye
224
What is an example of single innervation of the autonomic nervous system?
Energy stores
225
What is an example of dual innervation with non-antagonistic actions of the autonomic nervous system?
Salivary glands
226
What is an example of dual innervation with complimentary effects of the autonomic nervous system?
Reproductuve tract
227
What controls the autonomic nervous system?
Hypothalamus
Reflexes
