Metabolism - Lec 1 Flashcards
Define Metabolism
the process which produces energy and raw materials from food stuffs. this is used to support repair, cellular growth and division
and activity of the body, to sustain life.
what are the functions of metabolism
metabolism functions using metabolic pathways which produce waste.
- produce energy for cells to carry out tasks needed to sustain life
- store excess energy as fats and glycogen
- convert stored energy to usable energy at times of deficit
- provide starting building blocks for many processes
what is a catabolic pathway/process
Break down of large molecules into smaller ones (intermediary metabolites) - sugars, amino acids, fatty acids
releasing large amounts of free energy (ATP)
it is an oxidative reaction - hydrogen atoms are removed in this process
what are anabolic pathways/processes
synthesis of larger cellular components from intermediary metabolites (small molecules) Uses energy (ATP) released from catabolism reduction reaction - uses the H atoms released in catabolsim
food is the starting component of metabolism, what are the end products?
the waste products are,
co2
h20
urea
What are the products of Catabolic metabolism?
building blocks
energy - ATP
Acetyl CoA - important in metabolism for inter conversion of building blocks (extra detail)
biosynthetic reducing power used to drive ATP synthesis - NADH and NADPH
why does the human body need energy (hint to do work)
Biosynthetic work - anabolic process of building cell components.
Transport work - maintiang ion gradients
Special functions such as - Muscle contraction
neuronal conduction and osmotic work (kidney)
the human body uses chemical bond breakage to produce energy, how does this work ?
the breaking of chemical bonds to release energy (gibbs free energy G)
this is an exothermic reaction which releases energy (opposite is endothermic - uses energy)
What are redox reactions?
reduction and oxidation (one is not possible without the other)
OIL RIG
oxidation - loss of e- (removal of H+)
reduction - gain of e- (gain of h+)
the human body uses H carrier molecules
these are to accept electrons from fuel being broken down, then giving up those hydrogens to drive ATP synthesis. they are part of an energy cycle and their concentrations remain constant within the body.
what are they in both oxidised and reduced form?
NAD+ —–> NADH + H+ (ATP production)
NADP+ —–> NADPH + H+ (Biosynthesis)
FAD ——> FADH2
what essential item do we eat to maintain the function of H carriers?
B vitamins
How is ATP used to produce energy
think - what are the values?
ATP is cleaved into ADP then into AMP
this produces -31 KJ.mole-1 of energy - it is an exothermic reaction
the energy is porduced by the breaking of a high energy bond via phosphate hydrolysis
we only have enough ATP for a few seconds of energy.
Why?
it is a carrier of energy not a store, unlike fats.
we have very limited concentration of ADP
therfore we need a cycle of ATP - ADP
ATP is stable without catalysts - this allows the control of energy flow.
when ATP conc is high, we activate anabolic pathways (storage)
When ATP conc is low, we activate catabolic pathways
How do we do this?
The use of High and Low energy signals.
ATP,NADH,NADPH,FADH2 are singals of having high energy , and will trigger the activation of anabolic pathways
ADP,AMP,NAD+,NADP+,FAD are signals of low energy and will trigger the activation of catabolic pathways
under starvation how can we use ADP for energy
adenylate Kinase will convert 2 ADP into ATP and AMP
we can now make energy
AMP is a low energy signal
