BGM1002/L20 Metabolism Flashcards
Where does all energy on Earth originate?
The Sun
What 4 groups can all living organisms be classified into? (Considering energy sources)
Phototrophs
Autotrophs
Chemotrophs
Heterotrophs
Salivary amylase hydrolyses polysaccharides into what 3 products?
Oligosaccharides
Disaccharides
Monosaccharides
Pancreatic amylase hydrolyses oligosaccharides into what 2 products?
Disaccharides
Monosaccharides
Intestinal amylase hydrolyses disaccharides into what product?
Monosaccharides
Define metabolism.
Biochemical modification of chemical compounds in living cells and organisms
What is a catabolic reaction?
Breaking down of larger molecules
What is an anabolic reaction?
Reactions which build larger molecules from smaller ones
Give 3 features of catabolic reactions.
Degradative
Energy producing
Oxidative
Give 3 features of anabolic reactions.
Biosynthetic
Energy consuming
Reductive
Give 3 potential uses of energy in the body.
Mechanical work
Active transport
Heat production
Give 3 classes of macromolecules.
Storage
Structural
Functional
What are metabolic reactions which release free energy called?
Exergonic
What are metabolic reactions which use up free energy called?
Endergonic
How can endergonic reactions be induced in cells? (3)
Increased temperature
Increased [S]
Reaction linkage (coupled reactions)
How energetic is the gamma phosphoanhydride bond in ATP?
-30.7 kJ/mol
How energetic is the beta phosphoanhydride bond in ADP?
-27.3 kJ/mol
Why can’t AMP be hydrolysed?
Phosphoester bond is not very energetic and not easily hydrolysed due to lack of repulsion
What is the main role of GTP?
Protein metabolism
What is the main role of CTP?
Lipid biosynthesis
What is the main role of UTP?
Carbohydrate metabolism
Name 3 thioesters.
Acetyl CoA
Succinyl CoA
Fatty acid CoA
Why are thioesters easily hydrolysed?
High delta(G)
What does NAD+ stand for?
Nicotinamide adenosine dinucleotide
What is the purpose of NAD+?
Transport of hydrogen/electrons
Describe the general movement of electrons.
From one atom with lower affinity (reductant) to one with greater affinity (oxidant)
Where do hydrogens bind in FAD?
Across isoalloxazine group
How is hydrogen broken up in FADH2? (2)
Two free radicals
No ionisation
How are metabolic pathways controlled? (3)
Negative feedback
Feed forward
Isoenzymes
Multi-enzyme compelxes
Compartmentalised
Reciprocal regulation
Summarise stage 1 of carbohydrate metabolism.
Breakdown of complex molecules into simple units
Summarise stage 2 of carbohydrate metabolism.
Conversion of simple units into acetyl CoA (or citric acid cycle intermediates)
Summarise stage 3 of carbohydrate metabolism.
Production of ATP by complete oxidation of acetyl CoA
How is metabolism altered by starvation?
Structural proteins broken down and used to drive energy generation
How is metabolism affected by obesity?
Anabolic reactions turn more ingested molecules into storage molecules
