Biochemistry and Metabolism Flashcards
(43 cards)
What’s an electrolyte?
Salts, acids (release hydrogen) and bases (take up H+ ions)
What substanceses reduce blood acidity?
Bicarbonate and Ammonia help remove excess hydrogen to regulate pH
State types of macronutrients
- Carbohydrates – sugars, starches containing C,H, O
- Lipids – insoluble in water, contain C,H, O
- Proteins – structural material. Enzymes, haemoglobin, muscles – contain amino acids
Chemical composition of glucose
C6H12O6
Molecular composition of triglycerides
3 fatty acid tails
1 glycerol
Composition of amino acids
An amine group and organic acid group
Define metabolism
All (bio)chemical reactions occurring in the body – inc catabolic and anabolic pathways
Whats a catabolic pathway?
- Break down complex molecules to simpler ones
- Exothermic – releases energy as heat and ATP
- Waste products carbon dioxide and water
Whats an anabolic pathway?
- Build up the complex molecules of life
- Endothermic – requires energy input to form ATP
- Storage of glucose in complex molecules
What is adenosine triosphosphate?
- Only form of energy used to power cell activities
- Temporary store of negry
- Release in one step chemical reaction – ATP -> ADP + Pi
- Adenine base, ribose sugar and 3 phosphate groups
Whats direct phosphorylation?
- Using creatine phosphate – like ATP but less efficient
- Quickly converts ADP to ATP by donating a phospahte group
- Immediate energy stores in muscles
- Not long term
- Uses enzyme creatine kinase
What chemical is used in direct phosphorylation?
creatine phosphate
Using enzyme creatine kinase
Whats creatine kinase?
- Enzyme catalysing direct phosphorylation
- Trapped in Muscles (if muscle damage its lost in blood stream)
- Diagnostic marker for myocardial infarction – increased CK
State ways to catabolise glucose
- Obtained free due to blood glucose after a meal
- Glycogenolysis – breakdown of glycogen stores in muscle or liver
- Gluconeogenesis – formation of glucose from other nutrients in the liver – eg. proteins
Can be catabolised completely:
glucose and oxygen -> water + carbon dioxide + 38 ATP and heat
State the metabolic pathway for catabolism of glucose
- Glycolysis (anaerobic pathway)
- (Transition – crossing into the mitochondria)
- Kreb cycle
- Electron transport chain (aerobic pathway)
Explain the process of glycolysis
- Both Aerobic and Anaebolic respiration
- Cytosol (cristae)
- Glucose (6c) broken to 2 pyruvic acid (3c) in cytoplasm
- Use 2 ATP and form 4 ATP so net gain of 2ATP
- Metabolites are oxidised (H+ and e- removed)
- Picked up by NAD+ carrier which is reduced into 2 NADH + H+ (used in electron transport chain)
- In anaerobic respiration – no oxygen – the pyruvate becomes lactic acid as NADH+H+ is oxidised back to NAD+)
- In aerobic oxygen is present and continues to kreb cycle
Explain the process of krebs cycle
- Mitochondria
Repeats twice for every molecule of glucose:
1. Acytlcoenzyme A (2C) binds with a 4C molecule to create citric acid (6C)
2. Carbon atoms removed as CO2 waste
3. 3 NAD+ are reduced to 3 NADH+H+ (taken to electron transport chain)
4. Carrier FAD reduced to FADH2 (Taken to electron transport chain)
5. 1 ATP also formed due to phosphorylation of ADP.
Explain the process of krebs cycle
- Mitochondria
Repeats twice for every molecule of glucose:
1. Acytlcoenzyme A (2C) binds with a 4C molecule to create citric acid (6C)
2. Carbon atoms removed as CO2 waste
3. 3 NAD+ are reduced to 3 NADH+H+ (taken to electron transport chain)
4. Carrier FAD reduced to FADH2 (Taken to electron transport chain)
5. 1 ATP also formed due to phosphorylation of ADP.
Explain the process of the electron transport chain
(oxidative phosphorylation)
- Mitochondria
- NADH+H+ and FADH2 pass hydrogen and electrons to
- Each NADH+H+ - 3ATP formed
- FADH2 carrier leads to 2 ATP formed
- These are oxidised and regenerated
- Hydrogens pass across protein pumps to intermembrane space by active transport
- Electron transport chain creates electrochemical gradient in mitochondrial membrane
- ATP synthase goes through chemiosmosis allowing hydrogens (protons) back to matrix – producing energy for condensation reaction ADP + Pi to ATP
- Oxygen used as terminal acceptor for electrons out the ETC and hydrogen out the ATP synthase to form water
32 ATP in whole process
Explain the process of the electron transport chain
(oxidative phosphorylation)
- Mitochondria
- NADH+H+ and FADH2 pass hydrogen and electrons to
- Each NADH+H+ - 3ATP formed
- FADH2 carrier leads to 2 ATP formed
- These are oxidised and regenerated
- Hydrogens pass across protein pumps to intermembrane space by active transport
- Electron transport chain creates electrochemical gradient in mitochondrial membrane
- ATP synthase goes through chemiosmosis allowing hydrogens (protons) back to matrix – producing energy for condensation reaction ADP + Pi to ATP
- Oxygen used as terminal acceptor for electrons out the ETC and hydrogen out the ATP synthase to form water
32 ATP in whole process
Whats transition including process?
- Movement of pyruvic acid into mitochondria for kreb cycle
- Pyruvate dehydratase converts each pyruvate into acetyl-coenzyme A (3C to 2C molecule that is breathed out)
- Redox reaction as hydrogen removed (pyruvate is oxidised) pick up by NAD+ which is reduced from NADH+H+
- One molecule of CO2 is removed as waste
What is NAD and FAD?
- co enzymes
- Glycolysis and krebs cycle include oxidation reaction (add O, remove H+ and e-)
- NAD and FAD are acceptors of the hydrogen as they are reduced – this hydrogen can be used in the electron transport change for phosphorylation
WHat are the products of glycolysis?
2ATP
2NADH + H+
After electron transport chin - 6ATP in aeobic respiration
Whats teh products of formation of acetyl coenzyme A?
2NADH+ H+
6 ATP - after ETC