Cell Respiration Flashcards
What is a calorie?
Energy contained in food.
Food labels use kilocalories which are 1000X greater than a calorie.
1 g of carbohydrates contains 4 K or 4000 calories.
Looking at the original whopper, there are
What is cellular respiration?
Where does it take place in a cell?
The process that releases energy from food in the presence of oxygen.
Depends on the step, glycolysis takes place in the cytoplasm of any organism.
If eukaryote, mitochondrion
If prokaryote, after glycolysis the steps take place on the plasma membrane.
What is the difference between aerobic and anaerobic?
aerobic = in air. Kreb’s cycle and ETC both require oxygen. Kreb’s does not use oxygen directly bnut without the ETC functioning, it can’t function.
anaerobic = without oxygen
Glycolysis runs without oxygen
What is the relationship between photosynthesis and cellular respiration?
The products of one reaction are the reactants of the other. It is a cycle.
What happens during glycolysis?
Using the image:
Glucose comes in and is split (lysis).
2 Pyruvic acid molecules are formed (each 3C)
2 ATP are released. (net of 2 ATP. 2 are invested, 4 are made, therefore 2 net)
2 NADH are formed
What is the advantage of glycolysis?
Although the energy yield is small, the process is super fast.
Thousands of ATP molecules per second!
What happens in the Kreb’s cycle?
What comes in? What comes out?
Where does it take place?
It takes place in the Matrix.
Acetyl-CoA adds the 2 carbons (acetyl) to the four-carbon molecule to make citric acid.
Though a number of steps, these molecules are released PER one pyruvic acid:
4 NADH
1 ATP
1 FADH2
3 CO2
What is the job of CoA?
Coenzyme A helps Acetyl join to the 4 C molecule. It doesn’t participate in the actual reaction as it is an enzyme.
CoA is similar to the function of Rubisco in the Calvin Cycle.
How are NADH and FADH2 similar?
How are they different?
Both carry high energy electrons.
Both bring the electrons to the ETC.
NADH drops off its electrons at Complex I.
FADH2 drops its electrons off at Complex II.
What does this mean? NADH makes more energy!
NADH = 3 ATP
FADH2 = 2 ATP
How efficient is cellular respiration?
About 36% of the energy stored in glucose is released as ATP. The rest?
HEAT!
How does creatine work? What are some potential dangers? Should creatine be regulated?
To keep muscles working, phosphate groups are attached to creatine to make creatine phosphate.
Creatine phosphate can attach them to ADP to make ATP.
Liver and kidney damage may occur-plus copious amounts of water must be ingested to avoid cramped muscles.
Yes! Considering the dangers that we know of/plus the ones that we don’t!
What is fermentation?
The step after glycolysis that takes place without oxygen.
Fermentation recycles NAD+ so that it can pick up electrons and H+ from Glycolysis.
Alcoholic fermentation
pg. 263
Alcohol and carbon dioxide are produced.
NAD+ is produced.
Performed by yeast.
Foods? bread can rise.
Lactic acid fermentation
Why necessary?
When pyruvate accepts electrons from NADH, lactate is formed.
NADH is now changed to NAD+
Performed by skeletal muscles and bacteria.
Foods? cheese, yogurt, pickles
How long can skeletal muscles perform without doing aerobic respiration?
90s
How does cyanide affect cellular respiration?
Cyanide changes the active site of Complex IV.
The electrons are prevented from binding to oxygen.
The chain shuts down.
No gradient/no ATP!
Lactic acid fermentation begins!
