Exam #3 Flashcards
This chapter is about one thing…it’s about how cells make ___.
ATP
Most life on earth acquires energy through ___________, followed by ________ _________.
photosynthesis, cellular respiration
Our energy comes from the sun. It is harnessed by plants. The chloroplast converts that light energy into _______ energy, in the form of organic molecules.
Photosynthesis requires some starting material, and that would be ___ and ____.
chemical
CO2 and H20
What is the most efficient way to do catabolism?
Respiration
Cellular respiration is a ________ breakdown
complete
Fermentation is an ________ breakdown
incomplete
The whole point of catabolism is to provide ________ for the manufacturing of ATP. ALL ABOUT MAKING ATP
energy
Organic fuel is oxidized, what does that mean?
It means the removal of electrons
If something is oxidized, it’s _______ its electrons.
losing
Reduction is the ______ of electrons
gain
If something is oxidized and loses its electrons, something else is reduced and _____ those electrons
gains
What kind of bond does CH4 have?
non-polar covalent bond
What does non-polar covalent bond mean, in terms of electrons?
Electrons are all shared equally
What kind of bond does CO2 have?
polar-covalent bond
What does polar covalent bond mean, in terms of electrons?
Electrons are not shared equally, oxygen is pulling on the electrons
Rule of thumb: watch the ________ !
HYDROGENS!
Electrons are transferred along with protons…what is a proton? A hydrogen atom. So if we’re transferring protons, we’re transferring hydrogens. Does Carbon gain or lose hydrogen’s in this reaction?
It lost all of them
Does the oxygen gain or lose hydrogens in the reaction?
It gained them, which means reduction
If you lose hydrogens, you’re ________
If you gain hydrogens, you’re ________
oxidized
reduced
It’s the _______ in methane that have the energy
electrons
In non-polar covalent bonds, electrons are ____ from the nucleus and have more energy
far
In polar covalent bonds, electrons are _____ to the nucleus and have less energy
close
What about electrons in glucose? Energy poor or energy rich?
Energy rich, non-polar covalent bonds
Glucose and fats are biologicals fuels…we consume them and drain them of their energy…BY WHAT?
OXIDATION. It’s the electrons that have the energy, we’re going to oxidize the heck out of them, get all those electrons!
This is the reaction that attaches an inorganic phosphate to ADP to make ATP. This is called _________.
phosphorylation
When you join a phosphate to something, it’s called __________.
phosphorylation
ATP synthesis is _________.
Endergonic
What is the equation or “process” for cellular respiration?
C6H12O6 + 6O2 –> 6CO2 + 6 H20 + energy (ATP+heat)
What is the delta G for cellular respiration?
Delta G = -686 kcal/mole
How much energy is released when glucose is catabolized?
-686 kcal/mole
How does aerobic glucose catabolism compare with processes like the combustion of methane? How is it different?
They’re similar in that, glucose catabolism and combustion of methane are both…
Exergonic…
Organic fuel is oxidized (CH4 and C6H12O6)…
And oxygen is the oxidizing agent.
That said, this is not combustion. It’s not even a single reaction. Glucose catabolism is a process.
Also, unlike the combustion of methane, glucose catabolism is going to have many reactions. Steps. Glucose catabolism.
The words electrons and ________ are used interchangeably
hydrogens
H’s are eventually transferred to O2, but are FIRST transferred to chemicals known as _________, which will hold them for a time…hold them…
coenzymes
What are coenzymes?
Small molecules required by some enzymes.
Are coenzymes enzymes?
NO, THEY ARE NOT ENZYMES
Coenzymes are like a substrate of an enzyme. They will _____ to the enzyme. Like the substrate, they will be chemically _______ in the reaction.
bind, altered
Coenzymes have a very specific purpose, which is to serve as a molecular _____.
handle
Why are we taking the H’s from glucose?
They have ENERGY!
You take the H, you don’t want to lose track of the H…it’s so small…you need to chemically/covalently attach it to something that can serve as a _____ to carry the H to where it can be utilized for its energy content.
handle
What are three common coenzymes?
NAD+, FAD, Coenzyme A
Which of the three doesn’t carry H?
Coenzyme A
What is the main coenzyme?
NAD+
To be more specific, NAD+ carries one complete __ and one ______.
hydrogen, electron
EXAM QUESTION:
When NAD+ is reduced, what does it carry?
2e- and 1 p+
What is the reduced form of NAD+?
NADH
What is the difference between NAD+ and NADH?
The H, which is one electron and one proton.
Where is the other electron? Ah, there’s a charge…a charge where?
NAD+
NAD+ is an electron carrier that keeps the electrons _______.
energetic
How much energy is lost as we transfer electrons from glucose to NAD+?
Very little energy is lost
What is NAD+ specifically?
Two nucleotides join together…
Nicotinamide adenine dinucleotide
In NAD+, the two nucleotides are joined together by their __________.
phosphates
What’s important about NAD+?
It carries hydrogens
What kind of agent is NAD+?
Oxidizing agent
If you have a chemical with H’s, you can strip them away with _____.
NAD+
**Once NAD+ strips away the H’s, that chemical is ________, and NAD+ is _________.
oxidized, reduced
NAD+ does not carry both protons…it carries two ______ and one ______. So the other proton from that H goes into the _______.
two electrons, one proton.
solution
Start out with NAD+…NAD+ is _______…it delivers its electrons…NADH is ______.
NAD+ is _______, then NADH is ______…it goes back and forth
reduced, oxidized
reduce, oxidized
Who is the ultimate electron acceptor?
Oxygen
Who is the ultimate oxidizing agent?
Oxygen
EXAM QUESTION:
Who does NADH reduce?
Who does NADH give its electrons to?
THE ELECTRON TRANSPORT CHAIN
What are the four stages of cellular respiration?
Glycolysis
Pyruvate oxidation
Citric acid cycle
Electron transport chain
The first _____ stages of cellular respiration are going to catabolize glucose completely.
three. By the end of step 3, glucose will be completely catabolized.
Catabolism will occur through ________.
Oxidation
We’re going to _______ in glycolysis.
We’re going to _______ in pyruvate oxidation.
We’re going to _______ in the citric acid cycle
OXIDIZE, OXIDIZE, OXIDZE.
Stripping away electrons.
Many NAD+ are going to be _______.
Many NADH’s will be generated…
reduced
What happens in step 4? In step 4, _____ delivers those electrons to the….
NADH, electron transport chain.
When NADH delivers electrons to the ETC, NADH will become ________
oxidized, then back to NAD+
When do we make the ATP? Which stages?
1 and 3.
Literally Glycolysis and citric acid cycle
Which stage does not really make ATP?
Pyruvate oxidation
Which stage makes the most ATP?
Stage 4, ETC
It’s all about transferring those electrons…
We ____ the electrons in stage 1, we ____ the electrons i stage 2, we ____ the electrons in stage 3, and then _______ the electrons in stage 4 and that’s where ATP is finally made.
took, took, took, delivered
Where do these processes happen?
Cellular respiration beings in the _______. That’s where glycolysis happens. The product of glycolysis is imported into the __________. Everything else happens in the mitochondria. Stage 2 - pyruvate oxidation, stage 3 - citric acid cycle, stage 4 - ETC. So most of these things happen in the mitochondria. Glycolysis happens in the cytosol.
cytosol. mitochondria.
What’s the point of each stage? We’re _______ the sugar, creating the _______ coenzyme _____.
oxidizing, reduced, NADH
90% of ATP is made in stage __.
4
Glycolysis is a __ step pathway.
10
Glycolysis is run by __ enzymes.
10
Glycolysis means “sweet split.” The splitting of a sugar molecule. Glycolysis breaks glucose into __ smaller molecules.
2
In step 1, glucose is converted into the first _______ of glycolysis
intermediate
What is the other reactant, in addition to glucose, in this reaction?
ATP
What’s the other product?
ADP
So ATP was hydrolyzed. It’s phosphate was removed. Notice that the phosphate has become part of the glucose.
By burning and ATP to make the phosphate there, we’re making the sugar even more _______.
reactive. Even more energy rich…it’s got a phosphate now
Step 2 is a _________. Or isomerization.
Rearrangement. It rearranges the atoms and the sugar.