Metabolic processes Flashcards
First law of thermodynamics
Eng cannot be created or destroyed, only transfered
Examples of energy transformation how
Climbing a slide & sliding down- Converting kinetic energy to potential energy back to kinetic energy
Relate first law of thermodynamics to cell resp and photosynth
All of our energy comes from the food we it,
or from the sun in plants
its an examples of energy transformation
open vs closed system relate to bio
open - when eng can be lost to surroundings (oven)
closed - when eng stays in system
biological orgs are open systems
chemical potential eng
chem pot eng - the amount of chem eng that could be released
the greater the energy the more unstable to bond is
the more stable it is the more eng it take to break
exergonic vs endergonic processes
ex, spontaneity
exergonic - release eng,
change in eng - neg
spontaneous
becomes more stable
ex. cell resp
uses hydrolysis
endergoinic - absorbs eng
increase in eng
not spontaneous
less stable
ex. photosynth
uses synthesis
What is energy transformation by coupling
Exergonic reactions drive endergonic reaction
the energy outputted in exergonic is used in endergonic reactions
coupling and atp hydrolysis
atp hydrolysis when phosphate breaks off
phosphate from atp bonds to another molecule, makes it more reactive.
high eng bond on ATP and why it is weak
High eng bond on third phosphate
each phosphate has negative charge, constantly pushing away from one another
makes region unstable, easy to break
What are the 3 types of cellular work
Transport
ex. pumping things across barrier
Mech
ex. contraction of muscle cells
Chem
ex. synthesis of polymers from monomers
substrate lvl phosphorylation vs oxidative phosphorylation
sub lvl phos - direct way
phosphate is transferred directly from “food” to ADP -> ATP
uses Enzyme, found in kreb, glycolysis (Pep + ADP - > pyruvate +
ATP)
oxidative phos - indirect method
uses a redox reaction to transfer electrons to NADH or FADH2
before using it in making ATP (etc)
Principle of Redox reactions (defs)
Oxidation - loses electrons, is oxidized, is reducing agent
Reducing - gains electrons, is reduced, is oxidizing agent
When the reaction is reversed the one that gains and loses swap
can be seen as loss or gain of H
What is NAD+
oxidizing agent in metabolism
often gets reduced to make NADH
a coenzyme
What is NADH
reducing agent in metabolism
can get oxidized to make NAD+
stores energy that can make ATP
How can cell resp just be described as oxidation of glucose
what comes out of cell resp is H2O, CO2 and Eng
the glucose gets oxidized into CO2, it loses energy
the O2 gets reduced into H2O
C6H12O6+ 6O2 -> 6CO2+ 6H2O + Energy
Second law of thermodynamics
Energy transformation make the universe more disordered
entropy increases overtiem
it takes energy to have order
Heat and its relation to the second law of thermodynamics
organisms make give off heat
most random state of energy
increased entropy of the universe is caused mainly by heat
equilibrium meaning in chem reaction and life
means its at max stability
delta G = 0, equilibrium convert easily
reaction in closes system reach equilibrium and then do no work
if delta G = 0 in orgs they are dead (living things must not be equilibrium, disequilibrium causes work)
Diff sources of eng in human and uses
glycogen
- primary source of eng, only changes when it runs out
fats
- becomes main source when glucose is depleted
muscle tissue (protein)
- final resort, cells are breaking down (bad)
Equation of cellular respiration and goal
C6H12O6 + 6 O2 →6 CO2 + 6 H2O
to break glucose down and make 6 CO2
to collect eng in the form of atp
to move glucose electrons to O2, make 6 H2O
What are the 4 major stages of cell resp
glycolysis
oxidative decarboxylation(pyruvate oxidation)
krebs cycle
electron transport chain
what are the 7 enzymes used in cell resp
name, function, class
dehydrogenase - redox,1
kinase - phosphorylation, 2
lyase - cleavage, 4
decarboxylase - decarboxylation, 4
hydrase - hydration, 4
isomerase / mutase - isomerization, 5
synthase - synthesis, 6
What are the major steps of glycolysis
- atp-> adp
- isomeration
- atp->adp
- split into DHAP, G3P
- isomerization between G3P, DHAP
equilibrium - 2NaDH is made, dehydrogenase + phospho (p added)
- 2 Atp made, kinase, released
- isomerization
- water leaves (make PEP) lyase, released
- 2ATP made, kinase (puryvate)
energy investment phase vs energy payoff phase
energy investment phase - first 5
2 atp are put into glycolysis, invested
energy payoff phase - last 5
4 Atp are made from glycolysis, payoff
Why are all reaction in eng payoff phase doubled
the glucose breaks into 2 parts, the 2 parts each do the payoff phase
Which steps make or use energy in glycolysis
1.ATP - adp
3.ATP -> ADP
6.2 NADH is made
7.2 ATP is made
10.2 ATP is made
makes 4 atp
2 NADH
Purpose of fermentation
When there is no oxygen present, the cell can still make NAD+ for glycolysis to make ATP without O2
(usually made in ETC)
Process of lactic acid fermentation
2pyruvate
takes 2NADH, turns it into 2NAD+
becomes 2lactate
NAD+ goes to glycolysis
Process of Alcoholic fermentation
2pyruvate
CO2 leaves
becomes 2 acetaldehyde
gets 2NADH into 2NAD+
becomes 2Ethenol
NAD+ goes to glycolysis
Lactic vs alcohol fermentation
alcohol fermentation not in humans, yeast, makes CO2, has middle step.
Ethanol will not be converted back to pyruvate ever
Lactate can be converted back
both regen 2NAD+
impact of lactic acid fermentation on the body
builds up in muscles, transported to liver
used to be thought to cause soreness actually just swelling
allows you to make eng without O2
gets tiring because less eng is made
Why does anaerobic respiration cause fatigue
no CO2 is released or H2O
The NADH made from glycolysis has to be used up. less energy is made
Energy molecules made at the end of anaerobic respiraiton
just 2 ATP
usually glycolysis makes 2 NADH also
Process of oxidative decarboxylation (steps, reaction type, enzyme )
Pyruvate
release CO2, decarboxylation, decarboxylase
NAD+ -> NADH, redox, dehydrogenase
add coenzyme A, synthesis, synthase
Major steps in kreb cycle
- Coa leaves, join c4 - c2 makes citrate, synthesis
- isomerization
- NADH made, CO2 release, redox,decarbox
- NADH made, CO2 release, COA added, redox, decarbox, synth
- ATP made, COA leaves, sub lvl phose(kinase), lyase
- FADH2 made, redox
- hydration, rearrange molec, makes malate
- NADH release, recreate molec to restart, redox, makes OAA
How much energy from Krebs and pyruvate oxidation (what step )
per 1 glucose
Py oX - 2 NADH (2)
Krebs - 6NADH (3.4.8), 2ATP(5), 2FADH(6)
Purpose of electron shuttle
bring NADH into mitochondria
indirect
needs to get to etc
Glycerol phosphate vs malate aspartate shuttle
gly phos - converts to FADH2, less efficient, molecs don’t go into matrix
malate aspartate - stays as NADH, uses glutamate and other things to change back, more molec involved
humans do both
What are the main steps in Malate aspartate shuttle
- dehydrogenase in cytoplasm, takes electrons from NADH to OAA, makes Malate
- Malate enters mitochondria
- Dehydrogenase in matrix removes electrons, adds to NAD+ makes NADH
- OAA becomes Aspartate with glutamate help
- Aspartate leaves
- Aspartate becomes OAA with aKG
WHat are the main steps in glycerol phosphate shuttle
DHAP takes H from NADH
becomes glycerol 3 phosphate
glycerol 3p goes into inner mito space
H attaches to FAD making FADH2
Glycerol becomes DHAP, leaves
What are the 2 methods of ATP synthesis
Substrate lvl phosphorylation - Direct, uses phosphate transfer, in glycolysis, krebs
oxidative phosphorylation - indirect ATP formation through redox reactions involving O2 as a final electron acceptor, driven by ETC, phos starts off free
Proteins in electron transport chain
Complex 1 - takes 2e- from NADH, pumps protons out
Complex II only for FADH2, not a pump
ubiquinone (Q) - in bilayer, transfer e from Cl to CIII
CIII - pumps protons
cytochrome C - peripheral in IMM
CIV - pumps protons, leads electrons to O2, makes H2O
Which way is the ATP synthase facing
cell resp - Bulb always in matrix of mitochondria
Photosynth - bulb in stroma
What is the driving force behind the energy transformation in ETC
Oxygen
How is each step in ETC a redox reaction
Movement of electrons
redox is transfer of electrons
each step electrons are transferred to another complex one thing gets oxidized and another gets reduced
describe Chemiosmosis
high conct of protons outside
passive transport
high to low cont, gradient is electrochemical
explain how NADH and FADH2 produce diff amt of ATP
NADH powers 3 pumps
FADH powrs 2 pumps
Define proton motive force
Movement of protons causes conformational change in ATP synthase, makes ATP