BIO CH 3 Flashcards
catabolism
break down macromolecules and release ATP
Anabolic
use ATP to build macromolecules
Chemical energy
a form of potential energy where chemical bonds serve as a store of energy and have the potential to be used to do work
exergonic reactions
release energy, are spontaneous reactions (negative Gibbs free energy)
-EXergonic reactions means that free energy is EXiting the system
endergonic reactions
require energy, are non-spontaneous processes because they require energy input to proceed to final state
What is ATP
energy source
is an RNA nucleotide/RNA nucleoside triphosphate
difference between RNA and DNA
RNA- ribose sugar (OH on 2’)
DNA- Deoxyribose sugar (H on 2’)
Component of ATP
- adenosine
- ribose sugar
- 3 phosphate groups
Difference between ATP and RNA nucleic acid
RNA has 1 phosphate, ATP has 3 phosphate groups
___ reactions breaks the high potential energy bonds of phosphate to release free energy
hydrolysis
What is reaction coupling
powering an energy-requiring reaction with an energy-releasing one, resulting in a negative Gibbs free energy (exergonic)
Mitochondria make ATP through ____, which is a _____process
cellular respiration
catabolic
The intermembrane space of mitochondria is
acidic
Mitochondrial matrix contains its own
circular DNA and ribosomes
Chloroplasts contains its own
circular DNA and ribosomes
What is the endosymbiotic theory
mitochondria(aerobic) and chloroplasts(photosynthetic) were once free-living bacteria, then internalized.
Aerobic cellular respiration is a ___ pathway that requires ____
catabolic
oxygen
Glycolysis converts ___ into ____ and is an ____ process
glucose
pyruvate
anaerobic
Where does glycolysis take place
cytosol
During glycolysis, NAD+ is ___ to NADH
reduced
What are the two phases of glycolysis
energy investment phase
energy payoff phase
Where is glucose phosphorylated by in the cytosol
glucokinase and hexokinase (only have to know hexokinase for the DAT though)
phosphorylation is
non-reversible
What is glucose called after phosphorylation?
glucose-6-phosphate
What is an isomerase
an enzyme that modifies glucose-6-phosphate into fructose-6-phosphate
What steps of glycolysis hydrolyze ATP?
Glucose-> Glucose-6-phosphate
Fructose-6-phosphate-> fructose-1,6-bisphosphate
What enzymes phosphorylates fructose-6-phosphate?
phosphofructokinase (PFK), makes fructose-1,6-bisphosphate
What are the irreversible steps of glycolysis?
those that require the hydrolysis of ATP
PFK is an
essential regulatory enzyme
By the end of the energy investment stage, ____ and ____ are made and exist in equilibrium
glyceraldehyde-3-phosphate (G3P) and dihydroxyacetone phosphate (DHAP)
G3P and DHAP are ___-carbon sugars
3
Which of the sugars undergoes additional reactions in glycolysis
G3P
What is produced during the energy-payoff phase?
4 ATP (Net gain: 2), 2 pyruvate, 2 NADH (total- for each G3P- 2 ATP, 1 pyruvate, 1 NADH is produced)
The products of the energy-payoff phase are produced through
substrate-level phosphorylation
How many steps are in the energy-investment stage?
1-5
How many steps are in the energy-payoff phase?
6-10
What happens to the pyruvate molecules in the mitochondrial matrix?
They are decarboxylated, releasing CO2
Where do pyruvate manipulations occur in prokaryotes? Why?
the cytosol, because they have no membrane-bound organelles
Once pyruvate looses CO2, it is a ___ molecule
2-carbon
What happens to the pyruvate after is looses CO2?
It undergoes an oxidation to become a 2-carbon acetyl group
This oxidation reaction also reduces NAD+->NADH
Once made, what happens to the acetyl group?
It binds to Coenzyme A (CoA)
What are pyruvate manipulations carried out by?
pyruvate dehydrogenase
What do the pyruvate manipulations produce per glucose?
2 CO2
2 NADH
2 Acetyl-Coa
Other names for the Kreb’s Cycle
the citric acid cycle
the tricarboxylic acid (TCA) cycle
Where does the Kreb’s cycle occur?
- the mitochondrial matrix in eukaryotes
- the cytosol in prokaryotes
What is the first step of the Kreb’s cycle?
a 2-carbon acetyl-CoA joins 4-carbon oxaloacetate to form 6-carbon citrate
What happens to citrate once made?
Undergoes rearrangements, where it looses 2-carbons as CO2
What happens each time CO2 is released from citrate?
NAD+ is reduced to NADH
What happens to the 4-carbon molecule after CO2 is released?
It progresses through the rest of the Kreb’s cycle, producing GTP
How is GTP produced?
substrate-level phosphorylation
What is GTP?
guanosine triphosphate, an RNA nucleotide triphosphate (similar to ATP)
What happens to the 4-carbon molecule after GTP is made?
passes electrons to flavin adenine dinucleotide (FAD)
What is FAD?
an electron-carrying coenzyme similar to NAD+
What happens to FAD once made?
undergoes reduction to make FADH2
What happens to the 4-carbon molecule once FAD is made?
it transforms into oxaloacetate, reducing NAD+-> NADH in the process
The Kreb’s cycle produces
- 2 CO2
- 3 NADH
- 1 FADH2
- 1GTP
How many times does the Kreb’s cycle occur per glucose?
Twice- once for each Acetyl-Co-A/pyruvate
One glucose molecule results in what after going through the Kreb’s cycle?
- 4 CO2
- 6 NADH
- 2 FADH2
- 2 GTP
Oxidative phosphorylation encompasses what components?
electron transport chain and chemiosmosis
What is the electron transport chain (ETC)?
made up of proteins and molecules that pass high-energy electrons from one component to the next
With each transfer, the electrons release ___ that the ETC uses to form an _____.
free energy
electrochemical gradient
Chemiosmosis uses energy stores in the electrochemical gradient to _____
synthesis ATP