Stored energy.

-Water behind a dam

Energy cannot be created or destroyed, but it can be changed from one form to another.

The total energy in the universe is conserved.

Energy cannot be changed from one form to another without a loss of usable energy.

25% of gasoline -> kinetic energy

75% -> heat energy

Every cellular process increases the total entropy of the universe.

The entropy of the universe increases slowly but steadily.

 more disordered

(Chaos rules)

More organized

More potential energy

Less stable (entropy)

Less organized

Less potential energy

More stable (entropy)

Sum of cellular chemical reactions.

Reactants and products.

Reactants have more free energy than products.

Change in G is negative (reaction releases energy).

Products have more free energy than reactants.

Change in G is positive (reaction requires energy input).

Constantly being generated from adenosine diphosphate.

Composed of adenine and ribose (adenosine) and three phosphate groups.

Endergonic.

Enzymes have an allosteric site, which is where enzyme and substrate fit together:

True or False

Consider this reaction A + B -> C + D + energy, which is wrong?

-Reaction is exergonic

-ATP might not be required

- A + B are reactants, C + D are products

-All of the above

Usually a part of a series of linked reactions (strict control).

Begin with a particular reactant (A) and terminate with an end product (G).

A -> B -> C -> D -> E -> G

Reactions

(Metabolic Pathways)

Generally, enzyme activity increases as ________ _________ increases.

More collisions between substrate molecules and the enzyme.

Inorganic ions (copper, zinc, iron)

Organic molecules (not proteins)

- Coenzymes

                           * Vitamins ( vitamin deficiency reduces enzyme activity)

Enzymes can be activated and deactivated.

The process of activation is _____ and activated enzymes have a different 3-dimensional structure.

The end product binds with the enzyme's allosteric site.

This shuts down the pathway.

Loss of electrons (increase positive charge)

-electron donor

Gain of electrons (decrease positive charge)

-electron acceptor

A series of membrane-bound carriers that pass electrons from one carrier to another.

High-energy electrons delivered, and low-energy electrons leave.

Organisms that make their own food.

Start of food chain.

Chlorophyll absorbs solar energy and energizes electrons.

Electrons move down electon transport chain.

Solar energy -> ATP, NADPH

Electrons give off energy in heat and flourescent light.

Light Reaction

(Light Dependent Reaction)

CO2 is taken up and reduced to a carbohydrate.

Reduction requires ATP and NADPH

ATP, NADPH -> Carbohydrate

Calvin Cylce/ Dark Reaction

(Light Independent Reaction)

There are two specialized chlorophyll a molecules in the reaction center of Photosystem I

True or False

There are two specialized chlorophyll b molecules in the reaction center of Photosystem II

True or False

Electron flow can be traced from water to a molecule of NADPH.

Uses two photosystems (PS I and PS II)

Photosystem consists of pigment complex and electron acceptor molecules in the thylakoid membrane.

Pigment complex helps gather solar energy.

Only occurs in PS I

Pathways only results in ATP production and not NADP+ reduction or O2 release.

Thought to be the older mechanism

Provides additional ATP.

Oxygen is given off during the cyclic pathway of light reactions

True or False

A series of reactions that produce carbohydrates before returning to the starting point again.

Utilizes atmospheric CO2 to produce carbohydrates.

Includes:

CO2 fixation

CO2 reduction

RuBP Regeneration

CO2 is attached to RuBP

The result is a 6-carbon molecule which splits into two 3-carbon molecules.

Rubisco speeds up this reaction.

Rubisco is the abundant enzyme.

Rubisco can sometimes fix oxygen instead of CO2

True or False

Product of the Calvin Cycle (C3)

Exported to the cytosol (out of the chlorplast)

Can be converted to a variety of organic molecules:

fatty acids and glycerol

sugars, starch, cellulose

amino acid synthesis

Stomata close to save water

O2 concentration increases and CO2 concentration decreases

Rubisco starts to fix O2

Breakdown of food

Generates energy (ATP)

Different leaf anatomy:

Bundle sheath cells and mesophyll cells contain chloroplasts

Mesophyll cells are arranged concentrically around bundle sheath cells

-Kranz anatomy

Different mechanism to fix CO2:

They can avoid photorespiration

-In hot, dry climates,  net photosynthetic rate is about 2-3 times that of other plants.

CO2 is fixed in mesophyll cells

-PEP

-PEP carboxylas

      *Malate (C4)

Malate is moved to bundle sheath cells

-CO2 is released and refixed in Calvin cycle

              *Spatial separation

Requires more energy

C4 plants partition carbon fixation in space, while _____ partitions by time

During the night:

______ plants fix CO2, forming C4 molecules, which are stored in large vacuoles.

During the day:

C4 molecules release CO2 to Calvin cycle when NADPH and ATP are available

-Water conservation

Which reaction comes first in cellular respiration?

-Citric Acid Cycle

-Transition Reaction

-Glycolysis

-Electron Transport Chain

What happens during glycolysis?

-Pyruvate is formed

-Pyruvate is oxidized

-FAD is reduced

-Oxygen is used to generate water

A cellular process that requires oxygen and gives off carbon dioxide

-Most often involves complete breakdown of glucose to carbon dioxide and water.

C6H12O6 + 6 O2 -> 6 CO2 + 6 H2O + energy

Redox reaction

Glucose gets oxidized

Something needs to be reduced

Coenzymes:

NAD+ + 2e- + H+ -> NADH

FAD + 2e- + 2H+ -> FADH2

NAD+

NAD+ (oxidized) + 2e- + H+ -> NADH (reduced)

4 Steps:

1. Glycolysis

2. Transition Reaction

3. Citric Acid Cycle (Krebs Cycle)

4. Electron Transport Chain

Glucose is broken down into two molecules of pyruvate.

-In the cytoplasm of the cell.

This is known as:

Pyruvate is oxidized

NAD+ is reduced to NADH

"Waste" carbon dioxide is removed

High in energy

Generates NADH and FADH2

Production of additional ATP

Release of CO2

8 Reactions:

1-3: Energy investment steps:

Two ATP are used to activate glucose that splits into PGAL

4-8: Energy harvesting steps:

Oxidation of PGAL

Results in four high-energy phospate groups (PGAP and PEP), which synthesized four ATP

Substrate-Level Phosphorylation

What happens during the transition reaction?

-Pyruvate is formed

-Pyruvate is oxidized

-FAD is reduced

-Oxygen is used to generate water

End product of glycolysis (pyruvate) enters

-Transition reaction and citric acid cycle:

*Pyruvate is oxidized to CO2

*CO2 and ATP are transported out of ______ into the cytoplasm for the ETC.

What happens during the Citric Acid Cycle?

-Pyruvate is formed

-Pyruvate is oxidized

-FAD is reduced

-Oxygen is used to generate water

What happens during the ETC?

-Pyruvate is formed

-Pyruvate is oxidized

-FAD is reduced

-Oxygen is used to generate water

As electrons pass down the ______ ______ _____, energy is captured and ATP is produced.

Oxidative Phosphorylation

NADH drops electrons at the top of the stairs

FADH2 drops them at the second step

Each NADH has enough energy to create 3 ATP

FADH2 has energy to create 2 ATP

Aerobic respiration is approximately 18 times more efficient than fermentation

True or False

Glycolysis followed by reduction of pyruvate to either alcohol and CO2 or lactate

Anaerobic pathway

Can provide rapid burst of ATP

Common in muscle cells

Carbohydrates, fats, and proteins can be used as energy sources.

Metabolism are all chemical reactions in a cell.

Catabolism are reactions that break molecules down.

Anabolism are reactions that synthesize new molecules

The synthesis of ATP is an exergonic reaction.

True or False

Which is wrong? The active site of an enzyme:

-undergoes a slight change in shape when accomodating the substrate

-is the part of an enzyme where the substrate can fit

-can be used over and over again

-is not affected by environmental factors like temperature and pH

-can be occupied by a competing molecule that has a shape similar to the substrate

The allosteric site of an enzyme is

-the same as the active site

-not a part of the protein

-where ATP attaches and gives up its energy

-often involved in feedback inhibiton

-all of the above

The absorption spectrum of cholorophyll

-is not the same as that of carotenoids

-approximates the action spectrum of photosynthesis

-explains why chlorophyll is a green pigment

-shows that some colors of light are absorbed more than others

-all of the above

How many molecules of CO2 and PGAL are needed to synthesize one glucose molecule?

-1 CO2 and 2 PGAL

-2 CO2 and 4 PGAL

-3 CO2 and 1 PGAL

-6 CO2 and 1 PGAL

-6CO2 and 2 PGAL

CAM stands for chloroplast and mitochondria.

True or false

The NADPH and ATP from the light reaction

-are used to split water

-cause rubisco to fix O2

-replace the electrons of PS I and II

-cause electrons to move through the thylakoid membrane

-are needed to convert PGA to PGAL

Glycolysis requires O2

True or False

During cellular respiration, the Krebs Cycle "turns" twice per gluscose molecule. How many ATP, NADH, and FADH2 are produced during one turn of the Krebs Cycle?

-1 ATP, 3 NADH, and 3 FADH2

-2 ATP, 6 NADH and 6 FADH2

-1 ATP, 3 NAD+, and 1 FADH2

-1 ATP, 3 NADH, and 1 FADH2

-2 ATP, 3 NADH, and 2 FADH2