Download Notes-Cellular Respiration

Cellular Respiration
Chapter 9
1.A)Explain where organisms get the energy needed for life processes.
• Organisms get the energy they need from food.
• Energy stored in food is expressed as calories.
• Calorie
• amount of energy needed to raise the temperature of 1 gram of water by 1 degree Celsius.
• 1000 calories = 1 kilocalorie, or Calorie.
• Cells use all sorts of molecules for food:
• fats, proteins, and carbohydrates.
• each of these molecules varies because their chemical structures
• therefore their energy-storing bonds, differ.
• Cells break down food molecules gradually
• use the energy stored in the chemical bonds to produce compounds
• ATP powers activities of the cell
1B)Define cellular respiration.
1C)What is the equation for cellular respiration?
Cellular Respiration
• process in which cells form ATP by breaking down organic compounds
Equation for cellular Respiration:
• 6 O2 + C6H12O6  6 CO2 + 6 H2O + Energy
• Oxygen + Glucose  Carbon dioxide + Water + Energy
Why does it have to be broken down this way?
• cells have to release the chemical energy in food molecules (like glucose) gradually
• otherwise most of the energy would be lost in the form of heat and light.
1D)What does aerobic and anaerobic mean?
• Anaerobic
• no oxygen
• Aerobic
!
• uses Oxygen
1E) Explain the structure and function of the mitochondrion parts.
• Outer membrane
• Allows ions, nutrient molecules, ADP and
ATP to pass through
• Inner Membrane
• Allows O2, H2O and CO2 to pass through
freely
• Contained with in the inner membrane:
• ETC
• ATP Synthase
• Transport proteins
• Cristae- folds that increase the surface area
• Matrix
• Contains the enzymes for the Krebs Cycle
• Contains the H gradient for ATP creation
2A) What happens during the process of glycolysis?
http://www.youtube.com/watch?v=3z6dq-T68zs&list=RDsblPT7SYH6s
Glycolysis
(glucose oxidized to produce pyruvic acid) (LEO)
1.
occurs in cytoplasm
3.
6C compound split into 2 PGAL (3C)
2 ATP (activation energy) used to form new 6C compound
2.
4.
5.
6.
•
•
PGAL oxidized
4H removed - joined to coenzyme NAD+ - 2 NADH + 2H
formed
4 phosphates removed - joined to ADP to form 4 ATP
now have 2 pyruvic acids (3C)
• C3H4O3 (Molecular formula)`
net yield of 2 ATP
2B)Explain the differences between lactic acid and alcoholic
fermentation.
http://www.youtube.com/watch?v=DGq94gpKEbg
Fermentation (further convert pyruvic acid)
(NO OXYGEN)
1. Lactic acid fermentation (occurs in muscle cells)
(certain bacteria)
strenuous exercise uses up O2 faster than can be
resupplied and H accumulates (NAD not available for
glycolysis)
a)
pyruvic acid becomes electron (H) acceptor and is
converted to lactic acid (NADH oxidized)
b)
c)
d)
•
•
regenerates NAD+ so glycolysis can continue
lactic acid accumulates in muscles
increased acidity causes less contraction, fatigue, pain, cramps
( increase acid, decrease muscle contractions)
diffuses into blood to liver - converted to pyruvic acid when O2
available
2B)Explain the differences between lactic acid and
alcoholic fermentation.
2. Alcoholic fermentation
Examples: beer, wine, bread
Organisms: bacteria, yeast
• a. CO2 removed from pyruvic acid and H
added from NADH + H to form ethyl alcohol
(C2H5OH)
• b. NAD+ regenerated for glycolysis
• c. alcohol has much energy (can be used as a
fuel)
• http://www.youtube.com/watch?v=4SosPuWAg7g
2C.)Identify and explain the pathways the body uses to
release energy during exercise .
How does the body produce ATP during different stages of
exercise?
• For short, quick bursts of energy
• the body uses ATP already in muscles as well as ATP made by lactic acid fermentation.
• extra oxygen is required to get rid of the lactic acid produced.
• For exercise longer than about 90 seconds
• cellular respiration is the only way to continue generating a supply of ATP.
• intense exercise, a person will huff and puff for several minutes in order to pay back the built-up
“oxygen debt” and clear the lactic acid from the body.
• body stores energy in the form of the glycogen (carbohydrate)
• glycogen stores enough to last for 15 to 20 minutes of activity.
• After that, the body breaks down other stored molecules, like fats for energy.
Aerobic Respiration
Aerobic Respiration
• Requires oxygen
• Occurs in the mitochondria
• Steps of Aerobic Respiration:
1. Glycolysis
2. Forming acetyl CoA
3. Krebs cycle
4. ETC (Electron Transport Chain)
3A)Explain how acetyl CoA is formed.
Forming Acetyl Coenzyme A
• 1. pyruvic acid enters mitochondrial matrix
• 2. CO2 removed from 3C pyruvic acid 2C acetyl group
http://science.howstuffworks.com/
life/29543-assignment-discoverycellular-respiration-video.htm
• 3. Coenzyme A joins to 2C acetyl forming acetyl CoA (oxidized)
• 4. 2H released and NAD+ reduced to NADH
• TOTAL For 2 pyruvic acids or 1 glucose molecule:
• 2 CO2 removed
• 4H removed(2 NADH formed + 2H)
• 2 H2O used
3B.)Describe the stages and the products of the Krebs cycle.
Krebs Cycle: Citric Acid Cycle
•1. 2C acetyl CoA attaches to 4C oxaloacetic acid to produce citric
acid (6C-C6H8O7)- CoA released
•2. During 1 cycle: (1 pyruvic acid)
•a. 2 CO2 removed
•b. series of oxidations removes 8H (6H form 3NADH + 3H and
2H form 1FADH2)
•c. 1 ATP formed
•d. 2 H2O used
TOTAL 2 turns of cycle because there are 2 pyruvic acids or 1 glucose
molecule so:
4 CO2 removed
16H removed (12 H form 6 NADH + 6H and 4H form 2FADH2)
2 ATP formed
4 H2O used
3C)Explain how high energy electrons are used by the electron transport chain.
Electron Transport Chain (on cristae) animation
• 1. much energy in electrons held by 10 NADH2 and 2 FADH2
• 2. electrons from 24H move down series of coenzymes and
energy from them produces 34 ATP
• each pair of H from NADH yields 3 ATP (10 NADH = 30)
• each pair from FADH2 yields 2 ATP (2 FADH2 = 4)
• 3. role of oxygen is final acceptor of electrons (chain keeps
operating and forming ATP)
• a. also accepts protons (H+)
• O2 + 4e- + 4H+
• 6O2 + 24e- + 24H+
2H2O
12H2O
• 6H2O used in previous steps so net of 6H2O
3D)How many molecules of ATP are produced in the entire
breakdown of glucose?
Where is the ENERGY made?
• Glycolysis = 4 ATP
• Kreb= 2 ATP
• ETC= 34 ATP
• 40 ATP Formed (2 used in Glycolysis)
• 38 ATP net yield
• http://www.mhhe.com/biosci/bio_animations/M
H01_CellularRespiration_Web/index.html
• http://www.youtube.com/watch?v=3aZrkdzrd04&
list=RDsblPT7SYH6s
3E) Compare and contrast the difference between aerobic
and anaerobic respiration
Anaerobic
• No O2 required
• Occurs in the cytoplasm only
• Called Fermentation
• Only produces Max. 2 ATP
• Less efficient
• Produces alcohol using
Prokaryotes
• Produces lactic acid in
eukaryotes
Similarities
•Break down glucose
•Go through glycolysis
•Requies glucose
•Produces Energy
•involves pyruvic acid
•Both continuous process
•Makes at least 2 ATP
•Use 2 ATP
Aerobic
• Requires O2
• Occurs in cytoplasm and
mitochondria
• Steps: forming acetyl coA,
Krebs cycle, and ETC
• Produces 38ATP
• Efficient
• Performed by Eukaryotes
3F) What is the relationship between photosynthesis and
cellular respiration?
Photosynthesis
Cellular Respiration
• products of P.S.
• are reactants of cell respiration
• occurs in chloroplasts
• occurs in mitochondria
• endergonic
• stores energy
• light energy is converted into chemical
energy in bonds of carbohydrates
• occurs in the light
• autotrophs do it
• Exergonic
• releases energy
• chemical energy from carbohydrate
bonds is released and used to make ATP
• occurs in light and dark
• autotrophs and heterotrophs do it