Chapter 9 Flashcards
the break down of glucose (organic molecules) is……?
exergonic/catabolic
aerobic respiration
consumes organic molecules and O2 and yields ATP
anaerobic respiration
consumes compounds other than O2 and yields ATP
fermentation
- is a partial degradation of sugars that occurs without O2
* the breakdown of sugar into an acid or alcohol
is glucose the only “fuel” for an organism?
no there are also carbs, fats, and proteins
The transfer of electrons during chemical reactions releases ____stored in organic molecules. This released energy is ultimately used to synthesize ___
- energy
- ATP
redox reactions
Chemical reactions that transfer electrons between reactants are called oxidation-reduction reactions, or redox reactions
oxidation
a substance loses electrons, or is oxidized
reduction
a substance gains electrons, or is reduced (the amount of positive charge is reduced)
reducing agen
The electron donor is called the reducing agent
oxidizing agent
The electron receptor is called the oxidizing agent
During cellular respiration, the___is oxidized, and___ is reduced
- fuel (such as glucose)
- O2
is NAD+ a coenzyme?
yes
what is NAD+
As an electron acceptor, NAD+ functions as an oxidizing agent during cellular respiration
what is NADH
- an electron carrier
- this is NAD+ with stored energy (it has been reduced)
- uses this energy to help synthesize ATP
what is NADH’s job?
passes the electrons to the electron transport chain
does the electron transport chain pass electrons in one explosive reaction or in a series of steps?
in a series of steps
what pulls down electrons through the electron transport chain?
oxygen (O2)
-energy yielded from the process of the electron passing through the chain is used to regenerate ATP
where does glycolysis happen?
cytosol
what is the process that generates the most ATP?
oxidative phosphorylation (made up of electron transport chain and chemiosmosis) because it is powered by redox reactions
is ATP made in the citric acid cycle (krebs cycle) and glycolysis? if it is made through what is ATP made?
yes! but just a tiny bit
- substrate level phosphorylation
what is substrate level phosphorylation
directly phosphorylating ADP with a phosphate and energy provided from a coupled reaction.
what is the difference between substrate level phosphorylation and oxidative phosphorylation?
SLP will only occur if there is a reaction that releases sufficient energy to allow the direct phosphorylation of ADP. Oxidative phosphorylation is when ATP is generated from the oxidation of NADH and FADH2 and the subsequent transfer of electrons and pumping of protons. That process generates an electrochemical gradient, which is required to power the ATP synthase.
does glycolysis need oxygen?
nope!
what is the name of glycolysis’ two phases?
- energy investment phase
2. energy payoff phase
what is created from glycolysis?
- 2ATP (4 were created but two were invested so a net of 2)
- 2NADH (electron carrier) (+ 2H+ “not important”)
- 2pyruvate (+ 2H20 “not important”)
what do you invest into glycolysis?
ATP and glucose
when does pyruvate enter the mitochondrion?
when oxygen is present …in the mitochondrion the oxidation of glucose is completed
once pyruvate is in the mitochondrion what happens?
it goes through a process to become Acetyl coA which is what the krebs cycle uses
what is the krebs cycle’s main job?
to break down pyruvate to CO2 and while doing this you recieve other various things
what does the krebs cycle generate other than CO2?
1 ATP, 3NADPH, and 1 FADH2 (THIS IS PER PYRUVATE BUT REMEMBER GLYCOLYSIS GIVES YOU 2 PYRUVATE SO FOR ONE MOLECULE OF GLUCOSE YOU GET 2 ATP, 6NADPH, AND 2FADH2 THROUGH THE KREBS CYCLE)
which is stronger FADH or NADH?
NADH
where is the electron transport chain located?
in the inner membrane (cristae) of the mitochondrion
what is this “chain” made out of ?
a series of proteins
what is “dropped off” at the top of the chain? and what drops them off?
an electron which “falls down” to O2 and forms H2O
- NADH or FADH2 drops off electron
cytochromes
hemeproteins containing heme groups and are primarily responsible for the generation of ATP via electron transport.
- one of the proteins in the line of proteins you see in the chain that transports electrons
does the electron transport chain generate ATP?
nope it breaks the large free energy drop that would happen from joining the electrons (H2) and oxygen present into smaller steps that release energy in manageable amounts
–NADH and FADH are oxidized to by oxidizing agents in the ETC. Since the electrons are moving from something less electronegative to something more electronegative, free energy is released.
as the electron travels through the proteins what happens?
H+ is pumped from the mitochondrial matrix to the intermembrane space
what are the two stages of oxidative phosphorylation?
- electron transport chain
2. chemiosmosis
where is oxygen “waiting”? which is where water is made
at the end of the chain NOT THE ATP SYNTHASE
proton motive force
energy that is generated by the transfer of protons or electrons across an energy-transducing membrane
if after glucose there is no oxygen what happens?
fermentation happens!
what are two common types of fermentation?
- alcohol fermentation
2. lactic acid fermentation
what happens in alcohol fermentation?
pyruvate lets go of CO2 and becomes acetaldehyde which combines with the electron in NADH ( to become NAD+) and creates ethanol
what happens in lactic acid fermentation?
pyruvate combines with the electron of NADH (to become NAD+) and creates lactate
what do fermentation, anaerobic, and aerobic respiration have in common?
- use glycolysis
- all three use NAD+ as the oxidizing agent
obligate anaerobes
carry out fermentation or anaerobic respiration and cannot survive in the presence of O2
true or false: ancient prokaryotes are thought to have used glycolysis long before there was oxygen in the
atmosphere
true
fatty acids are broken down by beta oxidation and yield… (to help with cell respiration)
acetyl CoA and then continues cell respiration on normaly
what else can be used to make ATP other than glucose?
proteins, carbs, and fats
how do fats work in cell respiration?
Fats are digested to glycerol (used in glycolysis) and fatty acids (used in generating acetyl CoA)
how do proteins work in cell respiration?
Proteins must be digested to amino acids; amino groups can feed glycolysis or the citric acid cycle
how is cellular respiration regulated?
feedback inhibition
-If ATP concentration begins to drop, respiration speeds up; when there is plenty of ATP, respiration slows down
