Metabolism And Nutrients Flashcards
Basic structure of Carbs ?
At least 2 hydroxyl groups
Carbon
Describe a major form of Carb?
Starch - mix of amylose and amylopectin
Glycogen - similar to amylopectin
Simple nutrition of Carbs?
1-2 Monosaccharides = simple carb
2+ = Complex
Simple structure of fatty acids?
A long chain of carbon (Organic acids containing 12-26 carbon atoms) surrounded by hydrogen atoms and has a carboxyl group at one end
Difference between saturated and unsaturated fatty acids ?
Saturated have no more room for more hydrogen therefore they are linked by single bonds whereas unsaturated will have double bonds
What is the most abundant lipid?
Triglycerides constituting 95% of dietary fats
Simple roles of vitamins and minerals?
Complement carbs, fats and proteins
Regulate numerous bodily functions
Energy available for exercise
Vitamins are water and fat soluble
Main vitamins and function?(9)
B1 - found in active site of pyruvate dehydrogenase
B2 - Precursor of coenzymes for redox reactions
B6 - Coenzyme for aminotransferase and neurotransmitters
B12 - Serves as enzyme in fatty acid processing
Niacin - Precursor of NAD and NADP
Folate - DNA synthesis
Pantothenate - Contributes to CoA
Vitamin A - In retinas of the eye
Vitamin D - Involved in calcium absorption = bone health
Main minerals and function?(8)
Sodium - Main cation in extracellular fluids, needed for electrical transmissions, also maintains water content
Potassium - Interacts with sodium to do the same
Iron - embedded in proteins handling o2 and ETC
Zinc - Sits in active sites to help remove Co2
Calcium - Bone health and blood clotting
Copper - Cofactor for cytochrome - ETC
Manganese - cofactor for over a hundred enzymes in metabolism
Magnesium - Cofactor for hundreds of enzymes
Non metal minerals and function?
Chlorine - main anion in extracellular fluid, interacts with sodium to balance fluid and electrical levels. also produces digestive Hcl Acid
Phosphorus - phosphoryl groups attached to biological compounds
All reactions are ?
Governed by the principle of mass conservation
Reversible
Complex
What is metabolism?
The sum of chemical reactions occuring in a living organism or part of it
What is free energy change? equation?
Energy free for work.
^G = ^H - T^S
Change in energy = change in enthalpy (bond energy) - Temperature (kelvin) x change in entropy (randomness)
What are the 3 ^G and what do they mean?
Negative ΔG: Free energy of products is lower than reactants. The reaction is spontaneous, releasing energy - Exergonic
Positive ΔG: Free energy of products is higher than reactants. The reaction is non-spontaneous, requiring an input of energy - Endergonic
Zero ΔG: The reaction is at equilibrium, meaning there is no net change in the system.
Exergonic is favoured
What is Anabolism?
Growth, cell division and energy storage
What is Catabolism?
A series of reactions that break down biomolecules into smaller molecules
What are reedox reactions?
Oxidation? Reduction?
Equilibrium of gaining and losing electrons.
Oxidation = Accepting o2/losing hydrogen
Reduction = Accepts hydrogen/loses o2
Why do muscle cells differ?
Contractile proteins - overlap to contract
Myocytes - multinucleated forming tubes etc
Properties of Myosin?
Very large and abundant in muscle
2 large heavy chains and 4 small light chains
Light meromyosin forms filaments spontaneously
Heavy meromyosin forms cross bridges, hydrolyses ATP and binds Actin
Properties of Actin?
Main component of thin filaments, existing as G-actin (globular) or F-actin (Fibrous)
F-Actin forms trunk for attachment of tropomyosin and troponin
As well as increases ATP activity by releasing ADP and P
Sliding filament theory process?
1) Motor neuron stimulates muscle fiber triggering action potential which travels down sarcolemma via t-tubules
2) Triggers release of calcium which binds to troponin exposing binding site for myosin head
3) Myosin head binds to site, the ATP attached is hydrolysed pulling the filament along - power stroke
4) ADP + P is removed and ATP joins detaching the head from the site, once hydrolysed it will move again
5) Process continues while calcium is present, once it isn’t the site is covered again.
Explain the transmission of signals process?
1) Action potential reaches the axon terminal causing an influx of calcium ions into the presynaptic terminal
2) Vesicles fuse with membrane releasing Acetylcholine into the synaptic cleft
3) It diffuses across binding to receptors on the postsynaptic membrane
4) If it is depolarised sufficiently and passes threshold an action potential will be generated - excitatory potential, initiating neurotransmitter release to the target muscles
