energy reactions in cells Flashcards
Define metabolism
Metabolism is the set of processes which derive energy and raw material from foodstuffs and use them to support repair growth and activity of the tissue of the body to sustain life
Two main types of metabolic pathways
Catabolism
anabolism
Catabolism
Breaks down larger molecules into smaller ones
release large amounts of free energy
oxidative- release hydrogen atoms- reducing power
anabolism
Synthesises large important similar components from intermediary metabolites
use only really strong catabolism ATP
reductive (i.e. uses the hydrogen release from catabolism)
Four products of catabolic metabolism
- Building block materials
- Organic precursors (acetyl coA)
- Biosynthetic reducing power NADH NADPH
- ATP
What kind of work do cells do
- Synthetic work (Anabolism)
- Transport - membranes
- Specialised functions
~electrical work
~mechanical work
~osmotic work
Energy requirements of the body can be broken into three categories
Basal metabolic rate
activity(muscular work)
specific dynamic action of food
What happens when the energy intake of our food is greater than the energy requirement
1> growth- since as a new tissue
2. Production of adipose tissue
What kind of energy is used to drive reactions
Chemical Bond energy
Characteristic energy changes can be two types
exogonic-release energy
endogonic-require energy
A exogonic reaction has what kind of Gibbs free energy
Negative therefore is spontaneous
What is the change in the Gibbs free energy indicate
Whether the reaction spontaneous
it does not indicate the rate
Redox reactions
Oxidation is loss
reduction is gain
of electrons
Hydrogen carriers molecules contain what vitamin
B
NADH using production of
ATP
ATP+ H2O-> ADP+PI what is the change in the Gibbs free energy
-31 kJ per mole
therefore the reaction of spontaneous
ADP+Pi-> ATP+H20 how is this reaction driven
+31 kJ per mole
energy released is exergonic corrections used to drive
part of the free energy can serve as the chemical bond energy of the terminal phosphate group of ATP
When ATP is high what kind of pathways are activated
anabolic
High energy signals activate what
anabolic pathways ATP NADH NADPH FADH2
Low energy signals activate what
Catabolic pathways ADP AMP NAD+ NADP+ FAD
What are some of the most common energy storages
Glycogen
triglycerides
Some cells need to increase metabolic activity very quickly such as skeletal muscles what kind of energy stores do they also have
PhosphoCreatine
When is phosphocreatine produced
When ATP concentrations are high
if HP concentrations for suddenly the reaction reverses providing short-term boost of ATP
Enzyme that makes the phosphorcreatine
Creatine kinase
Isoforms of creatine kinase
MM muscle
BB brain
MB cardiac
What does both creatine and phosphocreatin spontaneously break down to
Creatinine
