General Biology 1 Exam 3 Study Guide

Know the process of Cellular Respiration (aerobic and anaerobic) and photosynthesis

Cellular Respiration:

1. Glycolysis

2. Pyruvate Oxidation

3. Krebs Cycle

4. Electron Transport Chain

Photosynthesis:

1. Light Dependent

2. Light Independent

What are heterotrophs? Autotrophs?

Autotrophs: Produce their own organic molecules through photosynthesis

Heterotrophs: Live on organic compounds produced by other organisms

What is decarboxylation?

In cellular respiration, pyruvic acid can be further oxidized by a transitional step involving a process called decarboxylation. In this step, an enzyme containing coenzyme A removes a carbon dioxide molecule to produce an acetyl group.

Does oxygen need to be present for glycolysis?

Glycolysis is the first stage of aerobic and anaerobic respiration. Unlike the rest of aerobic respiration, glycolysis does not require oxygen.

What is produced in our muscle cells during anaerobic respiration?

Lactic Acid.

What are electron carriers?

Electron carriers accept electrons and move them as part of the electron transport chain. In cellular respiration, NAD+ and FAD are the electron carriers.

What is chemiosmosis? Where does chemiosmosis occur? Enzyme used?

Chemiosmosis is the movement of ions across a selectively permeable membrane, down their electrochemical gradient. It takes place in the inner membrane of the mitochondria and the enzyme used is ATP Synthase.

How many ATP are made during glycolysis?

2 ATP.

What is substrate-level phosphorylation? Oxidative phosphorylation?

Substrate-Level Phosphorylation: A type of chemical reaction that results in the formation of ATP by direct transfer of a phosphoryl group to ADP

Oxidative Phosphorylation: Occurs when electron carriers are oxidized and ADP is phosphorylated to become ATP. It happens through the electron transport chain and chemiosmosis.

Which stage of cellular respiration uses cytochrome?

The Electron Transport Chain

How is energy used that is released from the movement of electrons in the electron transport chain?

The energy released is used to move hydrogen molecules removed from NADH and FADH across the membrane.

Why are components of the Electron Transport Chain embedded in the inner mitochondrial membrane?

-The components are in the proper orientation for the electrons to be transferred rapidly from one component to the next.

-The components are properly positioned to facilitate the transport of protons from the matrix to the intermembrane space

During photosynthesis, where does the carbon come from that is fixed into the glucose?

Carbon Dioxide.

What step results in the splitting of water?

Photosystem II

How many times does the Calvin Cycle have to turn?

3 Turns to incorporate enough carbon to produce a new G3P.

6 Turns to incorporate enough carbon for 1 glucose.

What is produced during the light reactions that are needed for the dark reactions?

ATP and NADPH

What is rubisco?

An enzyme that adds carbon dioxide to RuBP and oxidizes it by the addition of oxygen.

What happens in the thylakoid membranes?

Photosystems I and II are located in the thylakoids, this is where light dependent reactions take place.

What is the electron donor in photosystem II? What is the final electron receptor?

P680 is the primary electron donor in photosystem II. The final electron receptor is NADP.

What are photons?

A particle of light. It acts as a discrete bundle of energy. Its energy content is inversely proportional to the wavelength of light.

What are pigments? Accessory pigments? Chlorophyll A? Chlorophyll B? Carotenoids?

-Pigments: Molecules that absorb light energy in the visible range.

-Accessory Pigments: Light absorbing compounds that work in conjunction with chlorophyll A

-Chlorophyll A: Main pigment and only pigment that can act directly to convert light to chemical energy.

-Chlorophyll B: Accessory pigment that absorbs light wavelengths that chlorophyll A does not absorb.

-Carotenoids: Can absorb photons with wide range of energies. Decompose slower than chlorophyll so they show up more as light decreases in fall.

What is an antenna complex?

Hundreds of accessory pigment molecules. Gather photons and feed the captured light energy to the reaction center.

What are the different parts of the chloroplast?

-Thylakoid Membrane: Contains chlorophyll and other photosynthetic pigments

-Grana: Stacks of flattened sacs of thylakoid membrane

-Stroma: Semiliquid surrounding thylakoid membranes.

Where do the different reactions of photosynthesis take place?

-Light Dependent Reactions: Thylakoid membranes

-Light Independent Reactions: Stroma