Lecture 30 Metabolic Bioenergetics and Methods of Gene Regulation

__________ is the breakdown or degradation of molecules. Reactions release energy.

Catabolism

_________ is the build up or biosynthesis of molecules. Reactions utilize energy.

Anabolism

The three major purposes that living organisms require energy for are:

1. Performance of mechanical work in muscle contraction and other cellular movements
2. Active transport of molecules and ions
3. Synthesis of macromolecules and other biomolecules from simple precursors

Catabolic reactions are generally _________

oxidation

Anabolic reactions are generally _________

reduction

The synthesis of ___________ in specific membrane-bounded subcellular compartments makes their _________ between these compartments a vital part of eukaryotic metabolism.

metabolites; transport

Metabolic pathways are ____________ and has a first _________ step

irreversible; committed

All metabolic reactions are _________ and are controlled by regulating _______ that catalyze their first committed steps.

regulated; enzymes

Metabolic pathways in eukaryotic cells occur in specific cellular _________

locations

Fatty acid synthesis occurs in the _______, while breakdown occurs in the __________ and ____________

cytosol; peroxisome; mitochondria

To product more product, you need to ____ ____ ____ so that the reaction will keep moving forward.

take some away

The _____ and _________ do not take up glucose right away unlike other organs.

liver; pancreas

The _____ prefers to use glucose as fuel.

brain

The brain is able to switch to using ______ ______ as fuel.

ketone bodies

Anabolic and catabolic reactions regenerate _________

cofactors

Metabolic reactions release energy in ___________ steps, otherwise the release of energy would be explosive.

incremetal

______ is the final electron acceptor in aerobic respiration. (oxidative phosphorylation, ETC)

Oxygen

When delta G is zero, the reaction is at ___________

equilibrium

When delta G is very negative, the reaction is ____________ and highly _________

irreversible; exergonic

When delta G is positive, the reaction is ___________

unfavorable

________________ bonds in ATP contain a lot of energy which can be used to overcome unfavorable reactions. (coupled reactions for anabolism)

Phosphoanhydride

When Keq is greater than 1, delta G is ________ and the reaction ________ _______

negative; proceeds forward

When Keq is zero, delta G is ____ and the reaction is at ___________

zero; equilibrium

When Keq is positive, delta G is ________ and the reaction ________ __ _______

positive; proceeds in reverse

Keq = _______/_________

products; reactants

___________ are like money in the cell, they can be used to make DNA, RNA, ATP, GTP, CTP, and UTP

Nucleotides

High energy ________ compounds can be coupled to drive other reactions forward.

phosphate

1 kcal = _ kjoules

4

___ and ___ are important cofactors that must be regenerated for reactions. (electron carriers)

NAD; FAD

There are many different cofactors that carry different groups which need to be _________ after they are used.

regenerated

Vitamin _ is important for clotting

K

_ vitamins are water soluble

B

Vitamins _ and _ are important antioxidants.

E; C

Vitamin _ is important for the regulation of calcium and phosphate metabolism.

D

Vitamin _ is important for vision, growth, and reproduction.

A

Redox reactions (gain or loss of electrons) are catalyzed by _______________

oxidoreductases

Single replacement reactions are catalyzed by ___________

transferases

Double replacement and acid-base reactions are catalyzed by __________

hydrolases

Decomposition reactions are catalyzed by ______

lyases

Isomerization reactions are catalyzed by __________

isomerases

Synthesis reactions are catalyzed by _______

ligases

Metabolic reactions are regulated by ________ modification or __________ control

covalent; allosteric

Metabolic processes can be regulated by _______ control which controls the amount of enzymes.

genetic

The most important post-translational modification of an enzyme is _______________ which can activate or inactivate a protein.

phosphorylation

The allosteric site of an enzyme is any site other than the ______ site

active

Genetic control of metabolic processes is ______ than controlling the catalytic activities of enzymes via modification or allosteric control.

slower

Allosteric effectors are often __________, ________, or _________.

substrates; products; coenzymes

The first reaction of many biosynthetic pathways is often inhibited by the ultimate _______

product

_______ phosphorylate proteins.

Kinases

____________ dephosphorylate proteins.

Phosphatases

Insulin is an ________ hormine (stimulates build up of glycogen from glucose) which activates a phosphatase that activates glycogen synthase by _________________ it.

anabolic; dephosphorylates

Reactions can be controlled by regulating the movement of __________ through a reaction pathway from one compartment to another.

substrate

_______ control takes time to effect rates of metabolic pathways.

Genetic

__________ control can effect reaction rates negatively or positively.

Allosteric

A positive allosteric effector _________ Km which _________ the enzyme's affinity for the substrate.

decreases; increases

A negative allosteric effector _________ Km which _________ the enzyme's affinity for the substrate.

increases; decreases

During the _ state, the enzyme has low affinity for the substrate and binding is low.

T

During the _ state, the enzyme has high affinity for the substrate and binding is high.

R

___ is a negative allosteric effector of PFK-1 (glycolysis enzyme)

ATP

___ is a positive allosteric regulator of PFK-1 (glycolysis enzyme)

AMP