Chapter 4 - Energy

Question 0

What do cells use ATP for? 4.1

Answer 0

Cells use ATP for functions such as building molecules and movie materials by active transport.

Question 1

What is ATP? 4.1

Answer 1

• Adenosine Triphosphate
  ATP is a molecule that transfers energy from the breakdown of food molecules to cell processes.
• a wallet to carry money
• energy currency of the cell

Question 2

How is energy carried by ATP released? 4.1

Answer 2

Energy is released when a phosphate group is removed from the molecule.

Question 3

What is ADP? 4.1

Answer 3

ADP is a lower-energy molecule that can be converted into ATP by the addition of a phosphate group.

• Adenosine Diphosphate
• nearly empty wallet

Question 4

What does the breakdown of a simple sugar glucose yield? 4.1

Answer 4

36 ATP molecules

Question 5

What is chemosynthesis? 4.1

Answer 5

It is a process by which some organisms use chemical energy instead of light energy to make energy storing carbon based molecules.

Question 6

What is photosynthesis? 4.2

Answer 6

Photosynthesis is the process that captures energy from sunlight to make sugars that store chemical energy.

Question 7

How many calories per milligram do carbs and proteins yield? 4.1

Answer 7

4 calories per milligram

Question 8

What is chlorophyll? 4.2

Answer 8

It is a molecule in chloroplasts that absorbs some of the energy in visible light.

Question 9

What is a thylakoid? 4.2

Answer 9

A thylakoid is a coin-shaped membrane-enclosed compartment that contain light-absorbing molecules.

Question 10

What is the formula for photosynthesis? 4.2

Answer 10

6CO2 + 6H2O = C6H12O6 + 6O2

Carbon dioxide + water —— light, enzymes—— a sugar + oxygen

Question 11

What are the reactants and products of light dependent reactions? 4.2

Answer 11

Reactants : sunlight and water, ADP, NADP+

Products: oxygen and NADH and ATP

Question 12

What are the products and reactants of light independent reactions? 4.2

Answer 12

Reactants: CO2, ATP, NADPH
Products: glucose and NADP+ , NADP

Question 13

Where do light-dependent reactions take place? 4.2

Answer 13

• Within and across the thylakoid membranes

Question 14

Where do light-independent reactions take place? 4.2

Answer 14

• In the stroma of the chloroplasts

Question 15

What are the steps of the light-dependent reactions? 4.2

Answer 15

1. ) Energy from the sunlight is transferred, and H2O molecules are broken down and O2 molecules are released.
2. ) Energy is transferred to molecules that carry energy - ATP.

Question 16

What happens in a light-independent reaction? 4.2

Answer 16

1. ) CO2 is added to build larger molecules and light-dependent energy is used.
2. ) A simple sugar, usually glucose, is formed, and it stores some energy captured from the sunlight.

Question 17

What are 6-carbon simple sugars often used for? 4.2

Answer 17

• To build starches and cellulose

Question 18

Where does photosynthesis occur? 4.2

Answer 18

Chloroplast

Question 19

Where does cellular respiration occur?

Answer 19

Mitochondria

Question 20

What are photosystems? 4.3

Answer 20

They are two groups of molecules in the thylakoid membrane that capture and transfer energy.

Question 21

What is the electron transport chain? 4.3

Answer 21

• a series of proteins in the membrane of the thylakoid

- the passing if electrons along a series of molecules releasing energy as they go

Question 22

What does cellular respiration do? 4.4

Answer 22

Cellular respiration releases chemical energy from sugars and other carbon-based molecules to make ATP when oxygen is present.

Question 23

What’s the difference between aerobic and anaerobic? 4.4

Answer 23

Aerobic - needs oxygen to take place

Anaerobic - does not need oxygen to take place

Question 24

What happens in photosystem 2? 4.3

Answer 24

1. Energy is absorbed from sunlight and transferred to electrons (e-). High energy electrons leave the chlorophyll and enter an electron transport chain. 2. Enzymes break down water molecules. Oxygen, hydrogen ions (H+) and electrons are separated from each other. The oxygen is released as waste. The electrons from water replace those electrons that left chlorophyll when energy from sunlight was absorbed. 3. ) Electrons move from protein to protein in the electron transport chain, and their energy is used to pump H+ ions from outside to inside the thylakoid against a concentration gradient. The H+ ions build up inside the the thylakoid and the electrons move to photosystem 1.

Question 25

What happens in photosystem 1? 4.3

Answer 25

4.) Energy is absorbed from the sunlight again, and the electrons are energized and leave the molecules. 5.) The energized electrons are added to NADP+ which functions like ADP and NADPH is made. ATP Production - 6.) Hydrogen ions flow through a protein channel in the thylakoid membrane. The H+ ions is higher inside the thylakoid than outside. The chemiosmotic gradient is the difference in hydrogen ions which store potential energy. 7.) As ions flow through the channel, ATP synthase makes ATP by adding phosphate groups to ADP.

Question 26

What is ATP synthase? 4.3

Answer 26

It is an enzyme that allows hydrogen ions to pass through a membrane in order to make ATP from ADP.

Question 27

What is the process of the Calvin Cycle? 4.3

Answer 27

1. ) Carbon dioxide molecules are added to 5-carbon molecules already in the Calvin cycle. 6-carbon molecules are formed. 2. ) Energy - ATP and NADPH - from the light - dependent reactions is used by enzymes to split the 6-carbon molecules. 3-carbon molecules are formed and rearranged. 3. ) Most of the 3-carbon molecules stay in the Calvin cycle, but one high-energy three-carbon molecule leaves the cycle. After 2 3-carbon have left the cycle, they are bounded together to build a 6-carbon molecule such as glucose. 4. ) Energy from ATP molecules is used to change the 3-carbon molecules back into 5-carbon molecules. These stay in the Calvin Cycle and are added to new CO2 molecules that enter the cycle.

Question 28

What does glycolysis do? 4.4

Answer 28

It splits glucose into 2 3-carbon molecules and makes 3 molecules of ATP. - anaerobic

Question 29

What is lactic acid and what does it do? 4.6

Answer 29

C3H6O3 | It causes your muscles to burn during exercise.

Question 30

What is fermentation and what does it do? 4.6

Answer 30

Fermentation is an anaerobic process that allows glycolysis to continue. It does not make ATP. It removes electrons from NADH molecules and recycles NAD+ molecules for glycolysis.

Question 31

What molecule does fermentation provide to glycolysis? 4.5

Answer 31

NAD+

Question 32

Where do the Krebs Cycle occur? 4.4

Answer 32

Matrix of the mitochondria

Question 33

About how many ATP molecules does fat produce? 4.1

Answer 33

146 ATP molecules

Question 34

How many calories per milligram do lipids/fats yield? 4.1

Answer 34

9 calories per milligram

Question 35

What is the source of energy for organisms that use chemosynthesis? 4.1

Answer 35

Chemicals such as sulfides

Question 36

What are the two types of chlorophyll and what do they do? 4.2

Answer 36

The two types of chlorophyll, a and b, absorb mostly red and blue light and reflect green light.

Question 37

What happens from glycolysis? 4.4

Answer 37

2 molecules of ATP are used in order to complete glycolysis and only 4 ATP are made in the process => Net profit = 2 ATP

Question 38

What is the second part of the cellular respiration and what does it do? 4.4

Answer 38

Electron Transport Chain 3. )_ Energy is transferred to a chain of proteins in the inner membrane of the mitochondrion. 4. ) A large number of ATP molecules are made. Oxygen enters the process and is used to make water molecules. Water and heat are given off as waste products.

Question 39

What is the first part of cellular respiration and what does it do? 4.4

Answer 39

Krebs Cycle 1. ) The 2 3-carbon molecules from glycolysis further break down a series of chemical reactions into carbon dioxide (waste product). 2. ) NADH molecules are made. 2 ATP is produced and energy is transferred.

Question 40

How many ATP molecules are made from the breakdown of one glucose molecule? 4.4

Answer 40

2 from glycolysis | 34 or 36 from cellular respiration

Question 41

What is the formula for cellular respiration? 4.4

Answer 41

C6H12O6 + 602 ------ 6CO2 + 6H20 a sugar + oxygen ------ carbon dioxide + water (the opposite of photosynthesis)

Question 42

What happens specifically in the Krebs Cycle? 4.4

Answer 42

1. ) A pyruvate molecule is split into two-carbon molecule and and a molecule of carbon dioxide, which is given off as a waste product. High-energy electrons are transferred from the two-carbon molecule to NAD+, forming a molecule of NADH. The NADH moves to the elctron transport chain. 2. ) Coenzyme A bonds to the 2-carbon molecule made from the breakdown of pyruvate. This intermediate molecule goes to the Krebs Cycle. 3. ) This 2-carbon part is added to the 4-carbon molecule to form a 6-carbon molecule called citric acid and coenzyme A goes back to step 2. 4. ) The citric acid molecule is broken down by an enzyme and a 5-carbon molecule is formed. A molecule of NADH is made and moves out of the Krebs Cycle. A molecule of CO2 is given off as a waste prouduct. 5. ) The 5-carbon molecule is broken down by an enzyme. A four-carbon molecule, a molecule of NADH, and a molecule of ATP are formed. The NADH leaves the Krebs Cycle. Carbon dioxide is given off as a waste product. 6. ) Enzymes rearrange the four-carbon molecule. High energy electrons are released. Molecules NADH and FADH2, which is another electron carrier, are made. They leave the Krebs cycle and the 4-carbon molecule remains.

Question 43

What are the products from the breakdown of one pyruvate molecule? 4.4

Answer 43

- 3 molecules of carbon dioxide - 1 ATP molecule - 4 NADH molecules in the electron transport chain - 1 molecule of FADH2 to the electron transport chain

Question 44

What happens in the electron transport chain for cellular respiration? 4.4

Answer 44

1. ) Proteins inside the inner membrane of the mitochondrian take high-energy electrons from NADH and FADH2. The molecules of NADH and one molecule of FADH2 are used. 2. ) High-energy electrons travel through the proteins in the electron transport chain. The proteins use energy from the electrons to pump hydrogen ions across the inner membrane to produce a chemiosmotic gradient, just as in photosynthesis. The hydrogen ions build up on the inside of the inner mitochondrial membrane. 3. ) The flow of H+ ions is used to make ATP. Hydrogen ions diffuse through a protein channel in the inner membrane of the mitchondrion. The channel is part of the ATP synthase enzyme. ATP synthase adds phosphate groups to ADP to make ATP molecules. For each pair of electrons that passes through the electron transport chain, an average of 3 ATP molecules are made. 4. ) Oxygen finally enters cellular respiration. The oxygen picks up electrons and hydrogen ions to form water. The water molecules are given off as a waste product.

Question 45

What are the products of cellular respiration? 4.4

Answer 45

- Carbon dioxide from the Krebs cycle and from the breakdown of pyruvate before the Krebs cycle - Water from the electron transport chain - A net gai up to 38 ATP molecules for every glucose molecule - 2 from glycolysis, 2 from the Krebs cycle, and up to 34 from the ETC.

Question 46

What happens in lactic acid fermentation? 4.6

Answer 46

1. ) Pyruvate and NADH from glycolysis enter the fermentation process, and two NADH molecules provide energy pyruvate into lactic acid. As the NADH is used, it is converted back into NAD+. 2. ) 2 molecules of NAD+ are recycled back to glycolysis. The recycling of NAD+ allows glycolysis to continue.

Question 47

What happens in alcoholic fermentation? 4.6

Answer 47

1. ) Pyruvate and NADH from glycolysis enter alcoholic fermentation. Two NADH molecules provide energy to break down pyruvate into an alcohol and carbon dioxide. As the NADH molecules are used, they are converted back into molecules of NAD+. 2. ) The molecules of NAD+ are recycled back to glycolysis. The recycling of NAD+ allows glycolysis to continue.

Question 48

What are the products from the breakdown of one molecule of pyruvate? 4.4

Answer 48

1. ) 3 CO2 - waste 2. ) 1 ATP 3. ) 4 NADH molecules to the electron transport chain 4. ) 1 FADH2 to the electron transport chain

Question 49

Where does glycolysis take place? 4.4

Answer 49

Cell's cytoplasm