78 terms


Cell respiration
Gradual breakdown of glucose
Where are the two places that this process takes place in?
-Mitochondria (cristae + matrix)
How many ATP do you end up with in Glycolysis?
What are the three steps of respiration?
-Krebs cycle
-Electron transport chain
Where does glycolysis take place?
In the cytoplasm
Where does the Krebs cycle take place?
In the matrix of the mitochondria
Where is the electron transport chain?
In the cristae
The cytoplasm _______ for glycolysis?
Does not need oxygen
The mitochondria ______ for the krebs cycle and the electron transport chain?
Needs oxygen
How is NADH formed (describe using letters)?
NAD + e- + e- + H+ -----> NADH + H+
How many ATP can you get with one glucose?
Up to 38 ATP
If there is no oxygen in the mitochondria what happens?
The pyruvates will change to lactic acid or alcohol, in this process yeast and bacteria only get an extra 2 ATP which is much less than the usual 38 humans get.
Simple, complex, uses/consumes energy (photosynthesis)
breakdown, complex --> simple, releases energy
energy packet, storage, transfer, short-term
Sugars are oxidized by ______
How is NADH formed (use letters and description)?
When glucose is broken down it loses some hydrogen atoms. These hydrogen atoms have 2 protons and 2 electrons. NAD+ collects 2 e- and turns into NAD-. It then takes a positive hydrogen ion and turns into NADH, with the addition of yet another positive hydrogen ion it changes to NADH + H+.
Formula for Pyruvate
The 2 pyruvate that come out of gylcolysis have 3 choices:
-Go to mitochondria and krebs cycle if O2 is available
-No O2, stays in cytoplasm and becomes ethylalcohol + 2 CO2 = 2(C2H5OH)
-No O2, becomes lactic acid (in bacteria and muscle cells) 2(C3H6O3)

*all need enzymes
How is ATP like a compressed spring?
There is a crowding of negative charges in the tail of ATP, this is potential energy. This can be like a coiled spring because it too has potential energy. When bonds are broken, energy is released.
How does ATP do cellular work?
1 phosphate group is lost, which is then transferred to another molecule. In this process energy is also released.
How is ATP recycled?
When ATP loses a phosphate and turns into ADP, it just gains another phosphate later in a process and changes back into ATP. It continues to recycle itself many times.
How fast does a molecule recycle ATP?
Muscle cells recycle all ATP about once every minute. 10 million recycled every minute.
How does breathing support it?
While breathing we take in oxygen which is sent through the bloodstream to cells to perform respiration.
In cellular respiration _______ and _______ atoms from _______ are transferred to _______ atoms, thus forming _______
In cellular respiration...carbon...and...hydrogen...atoms from...glucose...are transferred to...oxygen...atoms, thus forming...H2O + CO2
Why is oxygen called an electron grabber?
Oxygen attracts e- very strongly.
A sugar molecule has ______ and _____ bonds, and during respiration these bonds break and bond with _______ atoms.
A sugar molecule has...carbon...and...hydrogen...bonds, and during respiration these bonds break and bond with...oxygen...atoms.
If you burn sugar in a test tube...
heat and light energy is released.
Compared with burning, cellular respiration is a more...
controlled fall of electrons.
In contrast to burning the oxygen reacts directly with glucose, Cellular respiration involves breaking down glucose in __ steps.
What happens in the electron transport chain?
Electron carriers pass electrons from one to the next. Each carrier holds them stronger than the one before. At the end, O2 grabs them and forms water.
At each electron transfer in the ETC, what happens?
A little energy is released, it is captured to form ATP.
What does glycolysis mean?
Splitting of sugar
What is the initial investment made that gets glucose to split?
What happens to the hydrogen atoms that fall of glucose in glycolysis?
They go to NAD to form NADH + H+
Does pyruvic acid still have energy stored in it?
It still holds most of the energy that was in the original glucose molecule.
Who was the Krebs cycle named after?
A biochemist named Hans Krebs.
The Krebs cycle finishes the breakdown of _______ to ____ releasing more _______ in the process. The enzymes for the Krebs cycle are dissolved in the _________ within a mitochondrion's inner membrane.
...pyruvic acid molecules...CO2...energy...fluid matrix...
How does pyruvic acid get inside the mitochondrion?
It diffuses across the membrane.
What are the pyruvic acid molecules converted to?
A 2 carbon compound called acetyl coenzyme.
In the pre-Krebs cycle what gas is released?
What do the 2-carbon molecules combine with to enter the Krebs cycle?
A 4-C acceptor molecule
What are the two parts of the ETC?
-E- transport chain
-ATP production by ATP synthase
Each transfer in the chain...
releases energy.
The energy made by the transfer of electrons is used to pump _____ across the membrane from where they are ___ concentrated to where they are ___ concentrated.
...hydrogen ions...less...more...
What does the pumping action of hydrogen ions store?
Potential energy
The hydrogen ions in the ETC do not stay packed together so they...
rush back through ATP synthase.
What does ATP synthase do?
Uses energy from flow of H+ to form ATP from ADP.
How many ATP can be generated this way?
34-38 ATP
What happens in glycolysis?
1. ATP gives up a phosphate and energy to glucose
2. A 6-C sugar phosphate is formed with a phosphate at the end
3. A second ATP gives up a phosphate and energy to glucose
4. A 6-C sugar phosphate is formed with a phosphate at each end
5. The 6-C chain breaks in half into two 3-C phosphates
6. The two 3-C molecules each lose 2 Hydrogens
7. NAD+ picks up the hydrogens and electrons to form NADH
8. Energy is released. ADP picks up phosphates to form ATP. (2 are formed)
9. 3-C molecules have lost a phosphate and have become pyruvate
10. Pyruvate will enter the mitochondrion to be completely broken down (oxidized.)
Cell respiration is a _______ reaction.
What are the two types of respiration?
Aerobic reactions:
Requirs oxygen, carried out by plants, animals, and some bacteria
Anaerobic reactions:
Does not require oxygen, carried out by yeast, some bacteria, and sometimes animals
Chemical equation for aerobic respiration
(C6H12O6) + 6 (O2) --> 6 (CO2) + 6 (H2O) + chemical energy
Pre-Krebs cycle occurs where?
In the cytoplasm
What happens in the Pre-Krebs cycle?
Pyruvate becomes Acetyl CoA and CO2 is made as a waste product.
What happens in the citric acid/Krebs cycle?
Acetyl CoA joins a 4-C acceptor molecule (forms 2 (CO2) and 1 ATP per molecule). NAD+ picks up e- and H+ to form NADH (energy rich)
How many times must the cycle turn for one glucose?
What happens in the ETC (from packet)?
Electrons move down chain/along carriers, to the end where they combine with O2 to form water.
Photosynthesis and Respiration are opposites
-make/use glucoes
-take in/out carbon dioxide
-give in/off oxygen
-Equations are flipped
If there is no O2 what are the two options?
-alcoholic fermentation
-lactic acid fermentation
Plants transport carbs mainly as what?
Where are the three places respiration takes place within the cell?
Glycolysis: Cytoplasm
Krebs Cycle: Fluid filled matrix
Electron Transport Chain: Cristae
In glycolysis how many ATP are made per pyruvate molecule?
What are the three products that are a result of the pre-Krebs cycle?
-acetyl CoA
6-carbon molecule in Krebs
5-carbon molecule in Krebs
4-carbon molecule in Krebs
Describes what happens in the Krebs cycle.
-Acetyl Coenzyme A enters the Krebs cycle. It bonds with the recycled 4-c molecule oxaloacetate to form a 6-c molecule, citrate,
-bonds are broken then reformed, CO2 is released, NAD is transformed into NADH
-Ketoglutarate, 5-C molecule is formed
-bonds are broken then reformed, CO2 is released, NAD is transformed into NADH
-4-C molecule is formed
-bonds are broken then reformed, ATP is created, FADH2 is formed, NADH is created
-Finally the 4-c acceptor that will re-enter the cycle, oxaloacetate is formed again
Per glucose, what molecules are formed in the Krebs cycle?
6 CO2
What happens in the ETC?
NADH and FADH2 go to the cristae. There, they drop off all of their electrons. The electrons move from carrier to carrier with a little bit of energy being released with each change. At the end, these electrons combine with oxygen and hydrogen ions to form water. approximately 34 ATP were created.
Where do all 38 ATP come from?
G: 2
KC: 2
ETC: 34
Nicotinamide adenine dinucleotide
Flavin adenine dinucleotide
How many carbons does acetyl CoA have, and why?
Pyruvic acid has 3, but when it combines with CoA is gives off CO2 so it loses one; therefore, acetyl CoA has 2 carbons.
In anaerobic conditions what do we and yeast cells produce?
Humans: lactic acid
Yeast: Ethyl alcohol and CO2