What are the 3 secondary structures?
What is the charge of acidic side chains?
What is the backbone of DNA called?
What joins amino acids together?
What are the different protein structures?
What is the process of forming glycoproteins called?
What is collagen composed of?
(glycine - x - proline)n
Where x can be:
What percentage of body weight does water make up?
What is the cytoskeleton made of?
Whare are microfilaments made of?
What are intermediate filaments made of?
What are microtubules made of?
What is the difference between trans and cis?
Cis is symettrical
What is the KW of water?
1 x 1014 mol/L
What are examples of important buffers?
How much Na and K does each molecule of ATP allow through the pump?
What is the osmolarity of the plasma?
What is the difference between the absolute refractory period and the relative refractory period?
Absolute is when all gates are opened and excitability is low
Relative is when gates are closed and excitability is increasing
What are examples of alpha, beta and C waves?
Alpha - proprioception, touch, fast pain
Beta - preganglionic autonomic fibres
C - heat, slow pain
What is acetylcholine removed from the NMJ by?
What is the cofactor?
Non protein component needed for activity
What is the co enzyme?
Complex organic molecule usually produced from a vitamin
What is FAD derived from?
What is NAD derived from?
What is the prosthetic group?
Cofactor covalently bound to enzyme
What is the apoenzyme?
Protein component of enzyme that contains a cofactor
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
Where is hexokinase and glucokinase found?
Glucokinase - liver
Hexokinase - everywhere else
What is KM and what does it indicate?
Concentration of the substrate at half the max v
High KM indicates a low affinity
What do the X and Y intersections on a Lineweaver-Burk plot represent?
Y - 1/vmax
X - 1/KM
What can you say about the first and second steps on an enzyme controlled reaction?
First is reversible
Second is rate limiting
What is an example of an enzyme that uses a sequential mechanism?
Lactate dehydrogenase (pyruvate to lactate)
What is an example of an enzyme that uses a random sequential mechanism?
Creatine kinase (creatine to phosphokinase)
What is an example of an enzyme that uses no ternary complex formation?
What is used to show enzyme mechanisms?
What is connective tissue composed of?
What is the ground substance composed of?
Glycoproteins and carbs
Where are desmosome junctions found?
Where are tight junctions found?
Intestine and stomach
Where are gap junctions found?
Cardial and neurons
What is the basement membrane composed of?
What is the basal lamina?
Secreted by epithelial cells which they sit on
What is the reticular lamina?
Connects basal lamina to underlying connective tissue
What are the 2 kinds of glands?
What do exocrine glands do?
Secrete into tubes
What do endocrine glands do?
Secrete into the blood
What are the 2 kinds of ducts from exocrine glands?
What are the 2 kinds of excretory components of exocrine glands?
What are the 3 kinds of secretion from a gland?
What is merocrine?
What is apocrine?
Example is sweat glands
What is halocrine?
Discharge whole cell
Example is sebaceous gland
What cells produce the secretions within glands?
Myoepithelial cells once they contract
What is the thyroid gland special?
Contains follicles of hormones (thyroxine) which is reabsorbed before being released into the blood
What is a single celled gland?
What are examples of exocrine organs?
Major silival gland
What are examples of endocrine organs?
What is the pancreas an example of?
An endocrine and exocrine organ
What is an example of loose connective tissue?
What are the 3 components of connective tissue?
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
What is collagen and elastin secreted by?
What does loose connective tissue do?
Attach epithelial to underlying tissue
What are 4 cells permanent cells in loose connective tissue?
What is an example of a dense regular connective tissue?
What is an example of a dense irregular connective tissue?
What are some proteins usually coupled to G proteins?
Where is Ca stored?
What is EC50?
Concentration of a drug to produce half the maximum effect
What are fibrous joints made of?
Dense fibrous connective tissue
What are the 4 basic cells in the epidermis?
What are merkel cells?
What are the 5 layers of the epidermis?
What happens in the stratum basule?
What happens in the stratum spinosum?
Desmosome junctions create 'spikes'
What is in the statum granulosum?
Granules of keratohyaline
What happens in the stratum lucadum?
Conversion of keratohyaline to keratine
What is unique about the statum corneum?
Where are melanocytes and merkel cells?
What binds cells of the stratum basule to the basement membrane?
What gives strength to the stratum lucidum?
What are the 2 layers of the dermis?
What is the papillary layer?
Loose connective tissue that protects against pathogens
What is the reticular layer?
Dense irregular connective tissue that attaches the skin to underlying tissues
What is found in the papilary layer?
What is unique about the subbaceous gland?
Only gland to secrete directly into the hair follicle
What are the 3 important hexoses?
What are disaccharides linked by?
What is the only carbon that can be oxidised?
What are 3 important dissacharides?
What is maltose formed from?
Glucose and glucose
What is lactose formed from?
Glucose and galactose
What is succrose formed from?
Glucose and fructose
What are the 2 glucose monomers in starch?
Amylase (alpha 1-4)
Amylopectin (alpha 1-4 and alpha 1-6)
What are glycoaminoglycans?
Unbranched polymers made from repeating units of hexuronic acid and an amino sugar
What is a property of glycaaminoglycans and where are they found?
Sticky and slimy, found in synovial fluid
What is a proteoglycan?
Formed from GAGs and proteins, more carbs than protein
What are mucopolysaccharides?
Genetic disorders caused by absence of the enzyme that breaks down glucoaminoglycans (GAGs)
Where are carbohydrates digested?
What enzyme acts on carbohydrates in the mouth?
Silivary amylase which breaks down alpha 1-4
What is the breakdown of carbohydrates like in the duodenum?
Similar to the mouth
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)
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
What can you say about cellulose and hemicellulose?
Cannot be digested so are broken down by gut bacteria, producing methane and hydrogen (smelly farts)
What is glucose immediately changed into in the liver and why?
Glucose-6-phosphate so it doesnt leave the cell
What is the reaction of glucose to glucose-6-phosphate controlled by?
Glucokinase in the liver
Hexokinase everywhere else
What controls the reaction of glucose-6-phosphate to glucose?
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
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
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)
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)
What is the first commited step of glycolysis?
Step 3 (F-6-P to F-1, 6bisP)
What do all fates of glycolysis regenerate?
What enzyme controls the reation of pyruvate to lactate?
What happens to lactate at the end of the cori cycle?
Transfered to liver and convered to pyruvate for gluconeogenesis
Where does glycolysis happen?
Where does the reaction pyruvate to acetyl coA happen?
Where is the enzyme that controls pyruvate to acetyl coA?
What are tissues that completely rely on glycolysis?
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)
Where is G-6-P converted into glucose?
Endoplasmic reticulum (G-6-P shuttled in and glucose and Pi shuttled out)
What enzyme controls F-1,6-bisP to F-6-P?
Where can fructose enter glycolysis?
Liver (dihydroxyacetone phosphate (DHAP) or glyceraldehyde - phosphate (GAP))
Adipose tissue (F-6-P)
Where can galactose enter glycolysis?
What does the pentose phosphate pathway produce?
What are the 2 stages of the pentose phosphate pathway?
1) Oxidation (irreversible)
2) Non oxidation (reversible)
What happens in the oxidation stage of the pentose phosphate pathway?
1) Generates NADPH
2) Converts G-6-P to pentose phosphate
What happens in the non oxidative stage of the pentose phospahte pathway?
Produces lots of 3, 4, 5, 6, 7 carbon sugars
What does breaking ethanol down require?
What do low levels of NAD lead to?
Increased blood lactate
Decrease blood glucose
What is vitamin C?
Where does the CIC happen?
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
What is pyruvate dehydrogenase inhibited by?
What is pyruvate dehydrogenase activated by?
What are the enzymes that control the 2 irreversible steps in the CAC?
Which of NADH and FADH2 cannot cross the mitochondrial membrane?
How does NADH in the cytoplasm pass its electrons into the electron transport chain?
Glycerol phosphate shuttle
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
How many proteins are in the electron transport chain?
Q-Cytochrome C Oxidoreductase
Cytochrome C Oxidases
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
What does the second protein of the ETC do?
Oxidises FADH2 and passes its electrons onto ubiquinone which becomes ubiquinol
Haem group captures stray electrons
What does the third protein of the ETC do?
Transfers electrons from ubiquinol to cytochrome C
Pumps protons into intermembrane space
How much cytochrome C does 1 ubiquinol make?
What does the fourth protein of the ETC do?
Passes electrons from cytochrome C to O2
Pumps protons into intermembrane space
What proteins of the ETC pump protons?
1, 3 and 4
What are the 2 parts of ATPsynthase?
F0 (membrane bound protein)
F1 (protrudes into mitochondrial matrix)
How many subunits does F0 have?
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
When does ATPsynthase rotate?
When 3 H+ enters
How much H+ is needed to generate 1 molecule of ATP?
How much ATP does NADH and FADH2 generate
NADH generates 2.5 per molecule
FADH2 generates 1.5 per molecule
What does uncoupling of the ETC cause?
Generation of heat instead of energy, as seen in brown fat
What are the 5 classes of lipids?
What is an example of lipid naming?
18:3 (9, 12, 15)
18 carbon long, 3 double bonds after carbon 9, 12 and 15
Why can essential fatty acids not be synthesised?
We cannot intoduce double carbon bonds after carbon 9
What is omega 3 derived from?
What is digestion of lipids by pancreatic enzymes (lipases) promoted by?
Emulsufication by bile salts and peristalsis
What are bile salts a derivitive of?
What is triacyglycerol degraded to in the small intestine?
2 fatty acids and a monoacylglycerol
What is cholesterol digested into?
Cholesterol and a fatty acid
What are phospholipids digested into?
Lysophospholid and a fatty acid
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
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
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
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
What happens to chylomicron renmants?
Go to the liver where glycerol is used to produce glycerol-3-phosphate
What causes fatty acid to be released from adipose tissue?
Hormone sensitive lipase being activated by noradrenaline
What is hormone sensitive lipase deactivated by?
High plasma glucose
What are examples of lipoproteins that carry lipids in the blood?
What is VLDL do?
Transfers tracyglycerol from liver to tissue
What does beta oxidation produce?
Where does beta oxidation occur?
What are the 3 stages of beta oxidation?
1) Activation of fatty acid in cytosol
2) Transport into mitochondria
3) Degradation to acetyl coA
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)
What does fatty acid use to enter the mitochonrial matrix?
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
What are the enzymes used in the carnitine shuttle?
Carnitine palmityl transferase I and II
What inhibits carnitine palmityl transferase?
What does not need to use the carnitine shuttle?
Short and medium chain fatty acids
What does each stage of beta oxidation produce?
1 acetyl coA
Carbon species 2 shorter
What is the net yield of ATP for beta oxidation?
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
What is excess acetyl coA converted into?
Where are ketones made?
Mitochondrial matrix of liver
What cannot use ketones for energy?
What cannot use fatty acids for energy?
Where does fatty acid synthesis occur?
How does acetyl coA get to the cytosol for fatty acid synthesis?
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
What is produed in the citrate shuttle?
NADPH which is used later for fatty acid synthesis
What is the product of fatty acid synthesis?
What is the rate determining step in fatty acid synthesis?
Acetyl coA and ATP to melonyl coA (catalysed by acetyl coA carboxylase)
What is acetyl coA carboxylase activated and inhibited by?
Activated by insulin
Inhibited by palmitoyl coA, glucagon and noradrenaline
How much NADPH does the formation of palmitic acid uses and where does it come from?
14 from citrate shuttle and pentose phosphate pathway
What are some specialised lipid classes?
What is cholesterol used to make?
Steroid hormones and membranes
What are eicosanoids derived from?
Omega 3 and omega 6
What does nitrogen to other molecule flow through?
What is transanimation?
Transfering amino groups through different molecules
What do all amino transfers rely on?
Pyridoxal phosphate cofactor (transfers amino group, derived from vitamin B6)
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
What tages cellular proteins that are to be degraded?
What are the fates of amino acids?
Left in tack for biosynthesis
Broken down into carbon skeleton and amino group
What is the fate of an amino group from a broken down protein?
Nitrogen disposed by urea cycle
What are the possible fates of carbon skeletons?
Glucose or glycogen synthesis
Fatty acid synthesis
What is amonia transported through the bloodstream as?
What is pyruvate converted into once it donates it accepts an amino group?
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)
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
How many amino acids are essential?
What are the 2 kinds of carbon skeletons?
Glucogenic (feeds into gluconeogenesis)
Ketogenic (feeds into CAC)
Where does the urea cycle happen?
Split between mitochondrial matrix and cytosol
What goes in and out of the urea cycle?
Ammonia goes in and urea comes out
How many enzymes are involved in the urea cycle?
What is the most common urea cycle defect?
UTC difficiency (X linked)
What is PKU?
Absence/difficiency of phenylalanine hydroxylase, causing a build up of phenylalanine levels which is toxic
What receptors does the autonomic and somatic nervous systems use?
Somatic uses iatotropic
Autonomic uses metatropic (G proteins)
What kinds of receptors does acetylcholine act on?
What receptors does noradrenaline act on?
How does the adrenal medulla work?
Sympathetic fibres innervate it and cause it to release adrenaline and noradrenaline into the blood
What are examples of post ganglionic fibres not following the rules?
Sympathetic cholinergic fibres innervate sweat glands
Some release neurotransmitters like peptides or NO
What is an example of antagonistic innervation of the autonomic nervous system?
What is an example of single innervation of the autonomic nervous system?
What is an example of dual innervation with non-antagonistic actions of the autonomic nervous system?
What is an example of dual innervation with complimentary effects of the autonomic nervous system?
What controls the autonomic nervous system?