module 2 microbio

What is cellular metabolism?

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

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

speed up chemical reactions, can be regulated by a cofactor that can activate or inhibit enzyme activity.

What is the difference between catabolism and anabolism?

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

ATP has the energy to ____, while ADP has the capacity to  ____ energy.

donate, accept

Chemotrophs can be subdivided into what two additional subgroups?

Organotrophs, which remove electrons from organic molecules, and lithotrophs, which remove electrons from inorganic molecules.

Chemotrophs utilize which form of phosphorylation?

Oxidative phosphorylation, in which energy released by the chemical oxidation of nutrients is used to reform ATP.

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

Glycolysis, Tricarboxylic Acid (TCA)/Krebs cycle, and the Electron Transport Chain. 

What are the reactants of glycolysis?

glucose, the co-enzyme NAD+ and ATP.

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

Fermentation or respiration. Fermentation should be utilized when there is a lack of oxygen, and makes less ATP. Respiration is an aerobic process and should be used when oxygen is available

How are the TCA and ETC related?

The ETC (electron transport chain) is the cellular process that occurs after the TCA (or Krebs cycle). The ETC uses the abundance of electron carriers created in the TCA to further create an abundance of ATP. 

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).

Proteases are used to catabolize what?

proteins

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

Carbohydrates, proteins and lipids; ipids are rich in energy

In what organelle does photosynthesis take place?

chloroplasts

In phosphorylation, the light reactions always occur where?

the membrane

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

ATP and NADPH

___CO2 +  ___ATP +  ___NADPH +  _____H20 →C6H12O6 +  ____ADP + ____NADP+

6,18,12,12,18,12

A-B → B-A

isomerases

Ab + C → A + Cb

Transferases

What determines the specificity of an enzyme?

Its active site, which is a unique chemical structure bound only by select target molecules. 

catatlysis

acceleration of a reaction by making it more energetically favorable

substrate

target of an enzyme

cofactor

metal ions that activate/enhance enzyme activity

enzyme structure is dictated by the ________ it encodes for

DNA sequence

rate of reaction and degree of activity of an enzyme depends on…

enzyme and substrate concentration, temp, pH

lipases

breaks down lipids

amylase

breaks down starches

catalase

breaks down H2O2 into water and oxygen

hydrolases

catalyze hydrolysis (breaking) chemical bonds with the addition of H2O

isomerases

catalyze rearrangement of bonds w/in a molecule to produce an isomer

ligases

covalent bonds join molecules together

lyases

cleave bonds other than using hydrolysis or oxidation

oxidoreductases

transfer electrons from reductant (election donor) to the oxidant (electron acceptor)

transferases

transfer a functional group

oxidation-reduction reaction

the transfer of electrons

electron acceptor (reduced)

gains electrons reducing its overall charge to be more negative

electron donor (oxidized)

loses electrons, mostly to oxygen

NADH oxidized becomes ____

NAD+

ATP

most widely used form of energy in cell