Questions to Answer

Biology – Study Guide for test over Cellular Respiration – Dec. 3, 2014

Chapter 7: The Working Cell: Energy from food Pages 136-155

Labs-

Food As Fuel - Review the analysis questions – What happened the energy when you burned food in your lab. Activty 7.3

Calorimeter measures calories – lets us know how much energy is available in our food

Diagrams:

Glycolysis- Know the numbers of ATP produced in each stage 2 ATP

Krebs Cycle – 2 ATP

Electron Transport Chain 32-34

autotroph/heterotroph comparison using photosynthesis and cellular respiration as an example of how autotrophs and heterotrophs are connected

Terms to know:

autotroph - an organism that can make its own food, also called producers

photosynthesis- using the solar energy from the sun plus carbon dioxide and water to produce sugars.

Producer – an organism that makes its own food

Heterotroph- organisms that can’t make their own food, also called consumers

Consumer – organisms that eat other consumers and or producers

cellular respiration – a chemical process that uses oxygen to convert the chemical energy stored in organic molecules(food) into ATP

kinetic energy – the energy of motion

potential energy- stored energy can be converted to kinetic energy

thermal energy – a type of kinetic energy where water and air molecules collide again and again and they give off heat

calorie – unit of measurement – the amount of energy required to raise the temperature of 1 gram of water by 1 degree Celsius

ATP- Adenosine triphosphate – energy currency for all living cells

Chemical energy- the energy stored in the bonds of ATP that can used to complete all cell work

aerobic respiration- respiration that uses oxygen

alcoholic fermentation- Anaerobic respiration where alcohol and carbon dioxide are the end products

lactic acid fermentation – Anaerobic respiration where lactic acid is the end product

anaerobic respiration –respiration that doesn’t require oxygen

electron transport chain- the chain where the electrons carriers NADH and FADH2 pass electrons to other carriers with the ultimate goal of producing ATP

metabolism- the sum total of all the chemical reactions that occur in an organism

glycolysis- the breakdown of sugar into pyruvate – takes place in the cytoplasm

Krebs cycle(citric acid cycle)- finishes the breakdown of pyruvic acid to carbon dioxide and releasing more ATP and also NADH and FADH2

ATP synthase—The enzyme embedded in the inner membrane of the mitochondrion where H+ ions go through to produce ADP +P into ATP

Questions to answer:

1. How much ATP is generated in glycolysis?

2 ATP

2. What is the energy investment/energy payoff relationship in glycolysis?

2 ATP must be used to start the process of glycolysis, an investment, followed by a payoff where 4 ATP are produced so a net gain of 2 ATP are produced from 1 glucose molecule in glycolysis

3. What is another name for the Krebs Cycle?

The Citric Acid Cycle the first intermediate in the Krebs Cycle

4. What is the role of NADH and FADH2 in cellular respiration?

They are energy carriers They are produced in glycolysis and the Krebs cycle to help or assist in the production of ATP in the Electron Transport Chain.

5. Where does the Krebs Cycle take place in the cell?

Fluid matrix of the mitochondrion’s inner membrane

6. Where does the electron transport chain take place in the cell?

Occurs in the inner membrane of the mitochondrion

7. Describe the two types of fermentation. Where do they take place and what are the products?

Lactic Acid fermentation takes place in muscle cells when there is no more oxygen and continues until the oxygen catches up.

Alcoholic Fermentation takes place in yeast and some bacteria and produces alcohol and carbon dioxide. (in the cytoplasm of the cell)

8. Where does the oxygen come from in cellular respiration?

We inhale the oxygen when we breath in

9. What happens to the CO2 in cellular respiration.

We exhale the CO2

10. Compare and contrast how autotrophs and heterotrophs obtain food.

Autotrophs make food from sunlight and water and carbon dioxide whereas heterotrophs eat the food the autotrophs made or eat other heterotrophs

11. Explain how cellular respiration harvests the energy in food.

Cellular respiration breaks down the food we eat into a usable form, ATP to complete all cell work.

12. Distinguish between kinetic and potential energy.

Kinetic energy is the energy of movement and potential is available (resting) but not being used yet

13. Explain what chemical energy is how cells release it from food.

Chemical energy is the energy in chemical bonds and the ATP molecule has 3phosphates that are like a tightly wound spring and when that last phosphate is released energy is released to do cell work, ATP must be produced from the breakdown of food.

14. Define calories and kilocalories as units of energy and how they are calculated.

unit of measurement – the amount of energy required to raise the temperature of 1 gram of water by 1 degree Celsius

there are 1000 calories in a Kilocalorie

measuring the increase in water temperature X 1000 =I Kcal

15. Describe the structure of ATP and how it stores energy.

Adenosine triphosphate( a tail of 3 phosphates, like a spring) when the spring is released energy is released The bond between the second and third phosphates is broken and so now you have ADP(adenosine diphosphate and phosphate) which can be recombined to form another molecule of ATP.

16. Give examples of work that cells perform. There are three types of cell work, describe each and give an example of each.

Chemical work – building molecules

Mechanical work- movement

Transport work – pumping solutes across a membrane

17. Summarize the ATP cycle. See the diagram

Adenosine triphosphate( a tail of 3 phosphates, like a spring) when the spring is released energy is released The bond between the second and third phosphates is broken and so now you have ADP(adenosine diphosphate and phosphate) which can be recombined to form another molecule of ATP

18. Describe the structure of the mitochondrion. See diagram in text

The highly folded inner membrane encloses a thick fluid called the matrix. Many enzymes and other molecules involved in cellular respiration are built into the inner membrane. The complex folding pattern of this membrane allows for many sites where these reactions can occur. This maximizes the mitochondrion's ATP production.

19. Summarize the three stages of cellular respiration and identify where ATP is made.

Glycolysis occurs in the cytoplasm and 2 ATP are produced here

NADH is also produced and 2 pyruvate

Krebs Cycle breaks the Pyruvate first to Acetyl- CoA to make more ATP(1 per turn and their are 2 turns per glucose molecule) and 4x2 = 8 NADH

and 1x2

FADH2 is

also where CO2 is released and then exhaled out. Takes place in the matrix of the mitochondrion.

The third stage the Electron transport chain takes the energy carriers NADH and FADH2 and to carry electrons down the electron transport chain to ultimately make water and more ATP. The hydrogen ions build up and are transported through the ATP synthase enzyme/protein to produce ATP from ADP + P. Takes place in the inner membrane of the mitochondrion.

20. Explain how fermentation in muscle cells is different from cellular respiration.

When oxygen is absent, your body can’t proceed to the Krebs Cycle, repeat glycolysis. In your muscles the product of glycolysis is lactic acid, which causes muscle cramps. Until oxygen levels are reestablished you will have pain and cramps. When oxygen is restored the pain and cramp will stop as the lactic acid is broken down.

21. Give examples of products that depend on fermentation in microorganisms.

Beer, wine, tofu, yogurt, buttermilk, soy sauce