CSF: Harvesting Chemical Energy Flashcards
why do we have ATP
is powers cellular network - is our energy currency (cashmoney)
building up
anabolism
breaking down
catabolism
ATP cycle definition
the transfer of energy between complex and simple molecules in the body with ATP as the mediator
conversion of glucose to ATP 4 main steps
- glycolysis
- pyruvate oxidation
- critic acid cycle (or Krebs cycle)
- electron transport chain
major categories of fuel (3)
- Carbohydrates
- Proteins
- fats
Carbohydrates broken down to what fuel
simple sugars
proteins broken down to what fuel
amino acids
fat broken down to what fuel
simple fats
where does glycolysis occur
cytosol
what three processes occur in the mitochondria
- pyruvate oxidation
- citric acid cycle
- oxidative phosphorylation
what is glycolysis
glucose to pyruvate
what is pyruvate oxidation
acetyl CoA
what is oxidative phosphorylation
electron transport and chemiosmosis
where is pyruvate oxidation and citric acid cycle
in the matrix
where is oxidative phosphorylation
across inner membrane
glycolysis and citric acid cycle occur at
substrate level
oxidative phosphorylation occurs at what level?
oxidative
glycolysis to oxidative phosphorylation electrons via?
NADH
citric acid cycle to oxidative phosphorylation electrons via?
NADH and FADH2
is oxygen required for glycolysis?
oui
glycolysis break down?
the lysis of glucose to produce two pyruvate molecules
ATP in the energy investment stage of glycolysis
2 ATP are invested
ATP in the energy payoff stage of glycolysis
4 ATP are produced
products in the net stage of glycolysis
2 ATP and 2NADH are produced (net)
does pyruvate oxidation require oxygen
yes!
what does the pyruvate oxidation stage produce?
- NO ATP
- 1 NADH per pyruvate (or 2 glucose)
- 1 CO2
what does the acetyl CoA enable? (going into citric acid cycle)
2 carbon acetyl group to enter citric acid cycle
what 4 products does the citric acid cycle produce
- 2 ATP
- 6 NADH
- 2FADH2
- 4CO2
(Per glucose)
does citric acid cycle require oxygen?
yes, it is aerobic process
what two molecules are electron donors in the transport chain?
FADH2 and NADH
series of reactions =
product of the first reaction is the substrate for the next
what does the citric acid cycle complete
extraction of energy from glucose
how much ATP does glycolysis produce per glucose?
2 net ATP per glucose
how much ATP does pyruvate oxidation produce per glucose?
no ATP
how much ATP does citric acid cycle produce per glucose?
2 ATP per glucose
how does Substrate phosphorylation generate ATP
by direct transfer (from a substrate) of a phosphate group to ADP
how do glycolysis and citric acid cycle make ATP
via substrate phosphorylation
how does oxidative phosphorylation generate ATP
the oxidation of NADH and FADH2 and the transfer of electrons and pumping protons
does electron transport chain require oxygen?
oui its aerobic
what two proteins are oxidized and how many electrons do they donate/gain
- NADH & FADH2
- donate 1 or 2 electrons
how do electrons transfer in the chain?
protein-to-protein
what happens at each protein in the electron transfer chain?
each electron gives up a little energy, this enables H+ ions to be pumped into the inter-membrane space
what does oxygen do to the electrons in the transport chain?
“pulls” electrons down the chain and is then the ‘final electron acceptor’ where its reduced to water
hydrogen rush down what chemiosmosis
down the concentration gradients
when the hydrogen goes down the intermembrane gradient what happens?
the turbine within ATP synthase to turn
what does the synthase turbine turning do?
enables the phosphorylation of ADP to ATP
how many ATP are produced during chemiosmosis
26 or 28 ATP
what stages make up oxidative phosphorylation?
Electron transfer chain and chemiosmosis
is oxygen required for ETC and chemiosmosis?
yes, oxygen is the final electron acceptor
what does cyanide do in oxidative phophorylation?
blocks passage of electrons to O2 = death of cell
how many (maximum) ATP are produced by one glucose?
30-32 ATP per glucose
What other sources (other than glucose) can we get ATP from?
fats, proteins and more complex carbohydrates generate ATP
what enters glycolysis and citric acid cycle at different points?
monomers
what is rate limiting for glycolysis
Phosphofructokinase
what produces insulin?
Beta cells in islets of langerhans pancreas
function of insulin
promote glucose uptake into cells for ATP production and liver storage
what produces glucagon?
alpha cells in islets of langerhans in pancreas
function of glucagon?
stimulates break down of glycogen to increase blood sugar levels
three things that happen when you lose insulin?
- no glucose in cells
- no ATP from glucose
- no glycogen stored
what is it called when the ability to produce or respond to the hormone insulin is impaired?
Diabetes mellitus
what does diabetes mellitus result in?
- abnormal metabolism of carbohydrates
- elevated glucose levels
- 7mmol/L fasting
Type 1 diabetes otherwise known as
insulin-dependent diabetes - requires insulin replacement
type 1 diabetes causes
- beta cells of pancreas destoryed; no insulin production
- often autoimmune, genetic or through environmental factors
who gets type 1 diabetes/when
- 5-10% of diabetics
- onset in children or adolescents
Type 2 diabetes otherwise known as
non-insulin-dependent diabetes
type 2 diabetes causes
body produces insulin, receptors are just not functional (insulin resistance)
who gets type 2 diabetes/when
- > 90% diabetics are type 2, usually usually over 40
- linked to obesity
two symptoms of diabetes are
- significantly increased hunger
- significant weight loss
