module two

n what organelle does photosynthesis take place?

the chloroplasts, they are double-membrane enclosed organelles. Each chloroplast contains the green photosynthetic pigment chlorophyll.

What is the difference between catabolism and anabolism?

Catabolism is the process of breaking down larger molecules into energy sources. Anabolism is the building up or biosynthesis of macromolecules from smaller molecular units into larger complexes

What is the primary function of enzymes and how are they regulated?

Enzymes speed up chemical reactions. Enzymes are not consumed during the reaction and can be used multiple times.

What are the two main strategies for replenishing cellular concentrations of NAD+ and when these strategies be utilized?

Fermentation and Respiration are the two strategies used by the cell to convert NADH back to NAD+. Fermentation occurs in the absence of oxygen while respiration occurs under aerobic conditions.

What are the three distinct stages in the catabolism of glucose?

Glycolysis is the first step of this process and yields 2 molecules of ATP. Next, by either fermentation (or respiration) 2 additional molecules of ATP can be produced. Last, the electron transport chain (ETC) produces 34 ATP via an oxidative phosphorylation event at the plasma membrane.

Excluding sugars, what are the other sources of energy? Which is highest in energy?

Polysaccharides, proteins and lipids can all serve as potential energy sources in the absence of sugar. Lipids are rich in energy, often having several reduced carbon molecules

Proteases are used to catabolize what?

Proteases are used to breakdown proteins

What are the byproducts of light reactions used for in dark reactions?

The ATP and NADPH produced via light reactions are used in dark reactions to convert carbon dioxide and water into organic carbon compounds as well as useful carbohydrates (a process called carbon fixation).

What are the reactants of glycolysis?

The reactants of glycolysis are glucose, the co-enzyme NAD+ and ATP.

What determines the specificity of an enzyme?

The specificity of an enzyme is heavily influenced by its active site—a unique chemical structure bound only by select target molecules. The structure is influenced by the amino acid composition of the protein as this in turn influences the fold, shape and 'appearance' of the enzyme. The active site (and it's target protein) can be thought of as a lock-and-key relationship. The active site provides a specificity (like a lock) that only specific target proteins can bind—much like how only a specific key will fit into, unlock and 'activate' a lock.

What is cellular metabolism?

a controlled set of biochemical reactions that occur in living organisms in order to maintain life.

How are the TCA and ETC related?

as the Kreb's cycle (TCA) produces an abundance of reduced electron carriers (NADH and FADH2), it fuels the ETC. As the electrons are transferred from NADH/FADH2 to terminal electron acceptors a proton motor force is generated, ATP synthase is activated and up to 34 molecules of ATP can be produced.

ATP has the energy to __________ while ADP has the capacity to ________ energy.

donate and accept

In phosphorylation, the light reactions always occur where?

it always occurs in the membrane. Similar to the electron transport chain, one of its main functions is to generate a proton concentration gradient to generate ATP.

Chemotrophs can be subdivided into what two additional subgroups?

organotrophs or lithotrophs,

Chemotrophs utilize which form of phosphorylation?

oxidative phosphorylation, oxidative phosphorylation utilizes the energy released by the chemical oxidation of nutrients to reform ATP.

Complete the following chemical reaction by placing the appropriate number in the blanks: __ CO2 + __ ATP + __ NADPH + __ H20→ C6H12O6 + __ ADP + __ NADP+

6 CO2 + 18 ATP + 12 NADPH + 12 H20 → C6H12O6 + 18 ADP + 12 NADP+

Identify the enzyme associated with the following enzymatic reactions: A-B →B-A ______________ Ab + C → A + Cb ______________

A-B → B-A (Isomerases) Ab + C → A + Cb (Transferases)

In the absence of sugars, are entirely different metabolic pathways used to process alternative sugar sources (fructose or lactose)?

No. Additional enzymatic steps are simply required at the beginning of catabolism to convert complex sugars into the usable forms of either glucose or a glucose intermediate (glucose-6-phosphate).