Chapter 3 - Cellular Energy Flashcards
catabolic processes
processes break down large macromolecules into smaller pieces and usually release energy in the form of ATP
anabolic processes
extract ebergy from ATP and use it to build larger, more complex macromolecules, where the energy is stores
definition of energy
the ability to do work(creating change in a biological system)
chemical energy is a type of ____ enery
potential
catabolic reactions ____ free energy, so they are an example of _____ reactions
release; exergonic
true or false: catabolic reactions are not spontaneous
false - they are spontaneous because they do not require energy input to proceed
anabolic reactions _____ free energy, so they are an example of _____ reactions
absorb; endergonic
true or false: anabolic reactions are spontaneous
false; non-spontaneous because they require energy input to proceed to the final state
why are ATP molecules unstable?
the three phosphate groups are all negatively charged and repel each other
how are bonds between phosphate groups broken in ATP?
hydrolysis
describe ATP hydrolysis reactions
spontaneous and exergonic
mitochondria has _ membranes
two - outer and inner membranes
the mitochondria ___ membrane contains many indentations called ___ that increase surface area
inner; cristae
region between outer and inner membranes of the mitochondria is called the ____ ____ and is ____
intermembrane space; acidic
the area deep to the inner membrane is called:
mitochondrial matrix
example of cells that contain many mitochondria
myocytes (human muscle cells)
example of cells that contain no mitochondria
red blood cells (lacks most organelles)
the matrix contains its own:
circular DNA and ribosomes
endosymbiotic theory
states that aerobic bacteria were internalized as mitochondria while the photosynthetic bacteria became chloroplasts
evidence for endosymbiotic theory
size similarities and the fact that mitochondria and chloroplasts contain their own circular DNA and ribosomes.
intermembrane space has low or high pH?
low pH (acidic)
glycolysis
converts glucose to 2 pyruvate
true or false: glycolysis is an anaerobic process
true - does not require oxygen
where does glycolysis occur
cytosol
two main phases of glycolysis
- energy investment stage (steps 1-5)
2. energy payoff stage (steps 6-10)
first step of glycolysis
glucose gets phosphorylated via one ATP hydrolysis to make glucose-6-phosphate. traps glucose inside the cell
first step of glycolysis enzyme name
hexokinase
true or false: 1st step of glycolysis is reversible
false - irreversible
2nd step of glycolysis
isomerase modifies G6P into F6P (fructose-6-phosphate)
3rd step of glycolysis
F6P gets phosphorylated to become fructose-1,6-bisphosphate. irreversible
3rd step of glycolysis enzyme name
phosphofructokinase (PFK)
which steps of glycolysis are irreversible
1, 3, 10
PFK is an essential ______ enzyme
regulatory - Levels of various molecules influence the speed with which phosphofructokinase functions, leading to regulation of the rate of glycolysis as a whole.
Fructose-1,6-bisphosphate is:
unstable, so it breaks down into 2 3-carbon sugars
Fructose-1,6-bisphosphate breaks down into:
dihydroxyacetone-phosphate (DHAP) and glyceraldehyde-3-phosphate (G3P)
DHAP and G3P exist in:
equilibrium
In order to favor the conversion of DHAP into G3P, and not the opposite, the cell must keep G3P levels:
low (Le Chatelier’s principle)
DHAP is converted to G3P via:
triose phosphate isomerase