BIO-111 Final Review

What is energy?

the capacity to do work/the capacity for change

What are energy changes associated with in biochemical reactions?

changes in the composition and properties of molecules

What are the two forms of energy?

potential and kinetic

What is potential energy?

energy stored as chemical bonds, concentration gradient, charge imbalances, etc.

What is kinetic energy?

the energy of movement

What is chemical energy?

energy stored in bonds

What is heat

energy transferred as a temperature difference

What is mechanical energy

the energy of motion

True/False: energy can be converted from one form to another

True

True/False: the laws of thermodynamics only apply to some types of energy

False

True/False: the laws of thermodynamics apply to all matter and all energy

True

True/False: the laws of thermodynamics describe energy conversions

True

What does the first law of thermodynamics tell us?

energy is neither created nor destroyed

True/False: when energy is converted from one form to another, the total energy before and after the conversion can be different

False

True/False: after energy is converted from one form to another, the total energy is the same as before the conversion

True

What does the second law of thermodynamics tell us?

when energy is converted from one form to another, some of the energy becomes unavailable to do work

True/False: although the transfer of energy doesn't change the total amount of energy in a closed system, the energy available to do work is always less than the original amount of energy

True

What is free energy?

energy that is available to do work

True/False: energy transformation is 100% efficient

False

True/False: no energy transfer is 100 percent efficient; some energy is always lost to disorder

True

What is entropy

a measure of the disorder in a system

True/False: energy is required to impose order in a system

True

True/False: a system can obtain order without energy

False

True/False: unless energy is applied to a system, it will be randomly arranged or disordered

True

True/False: in a closed system, with repeated energy transformation, free energy decreases and usable energy (disorder) increases

True

The first law of thermodynamics states that the total energy in the universe is _______?

constant

True/False: living organisms do not need a constant supply of energy to maintain order

False

True/False: living organisms must have a constant supply of energy to maintain order

True

What is metabolism

the sum total of all chemical reactions occurring in a biological system at a given time

True/False: metabolic reactions involve energy changes

True

True/False: metabolic reaction do not involve changes in energy

False

True/False: energy is released from food and harnessed by cells to do work

True

True/False: metabolism is the sum total of catabolism and anabolism

True

What are anabolic reactions?

reactions where complex molecules are made from simple molecules and an energy input is required

What are catabolic reactions?

reactions where complex molecules are broken down to simpler ones and energy in released

True/False: a chemical reaction occurs when atoms have enough energy to combine or change bonding partners

True

True/False: a chemical reaction does not involve energy changes

False

True/False: chemical reactions involve energy changes

True

What is a change in free energy (ΔG)

the difference in free energy between the products and the reactants in a reaction

True/False: changes in energy can be measured in calories or joules

True

Changes in energy can be measured in ______ or ______

calories; joules

If ΔG is negative, free energy is _______

released

If ΔG is positive, free energy is _______

required

True/False: if ΔG is negative, free energy is released

True

True/False: if ΔG is negative, free energy is required

False

True/False: if ΔG is positive, free energy is required

True

True/False: if ΔG is positive, free energy is released

False

True/False: if free energy is not available, some reactions can still occur

False

True/False: if free energy is not available, the reaction does not occur

True

What is ΔH

the total energy added or released in a reaction

What is enthalpy

the total energy in a system

What is entropy

the total unusable energy in a system

What does ΔH>0 mean?

energy has been added

What does ΔH<0 mean?

energy has been released

True/False: Larger changes in entropy result in more free energy being released (-ΔG)

True

True/False: Larger changes in entropy result in less free energy being released (+ΔG)

False

True/False: if a chemical reaction increases entropy, the products will be more disordered

True

True/False: if a chemical reaction increases entropy, the products will be less disordered

False

True/False: in hydrolysis of a protein into its component amino acids, ΔS is positive

True

What is ΔS

the change in entropy

In anabolic reactions, are simpler molecules or more complex molecules formed?

complex molecules

In catabolic reactions, are simpler molecules or more complex molecules formed?

simpler molecules

In anabolic reactions, is ΔS positive or negative?

negative

In catabolic reactions, is ΔS positive or negative?

positive

In anabolic reactions, is ΔG positive or negative?

positive

In catabolic reactions, is ΔG positive or negative?

negative

What is an exergonic reaction?

a reaction that releases free energy

Is ΔG positive or negative in an exergonic reaction?

negative

Is ΔG positive or negative in an endergonic reaction?

positive

What is an endergonic reaction?

a reaction that requires free energy

Are catabolic reactions exergonic or endergonic?

exergonic

Are anabolic reactions exergonic or endergonic?

endergonic

What is ATP?

adenosine triphosphate

What does ATP do?

captures and transfers free energy

True/False: ATP releases a small amount of energy when hydrolyzed

False

True/False: ATP releases a large amount of energy when hydrolyzed

True

True/False: ATP can phosphorylate, or donate phosphate groups, to other molecules

True

What are the three important components of ATP?

ribose sugar, adenine base, 3 phosphate groups

How many phosphate groups does ATP have?

3

How many phosphate groups does ADP have?

2

How many phosphate groups does AMP have?

1

True/False: the hydrolysis of ATP yields free energy

true

True/False: the formation of ATP is exergonic

false

True/False: the formation of ATP is endergonic

True

True/False: the formation and hydrolysis of ATP couple endergonic and exergonic reactions

True

True/False: the coupling of endergonic and exergonic reactions is not very common in metabolism

false

True/False: the coupling of endergonic and exergonic reactions is very common in metabolism

True

True/False: the hydrolysis of ATP releases free energy that drives an endergonic reaction

True

What are catalysts?

molecules that speed up the rate of a reaction

True/False: a catalyst is altered by the reaction

False

True/False: a catalyst is not altered by the reaction

True

What are enzymes?

proteins that act as catalysts

What is activation energy (Ea)?

the amount of energy required to start a reaction

True/False: enzymes raise the energy barrier for reactions

false

True/False: enzymes lower the energy barrier for reactions

True

What is the transition state?

the reactive condition of the substrate after there has been sufficient input of energy to initiate the reaction

What is a substrate?

the molecules on which an enzyme exerts catalytic action; the reactants of an enzyme-catalyzed reaction

What is the active site?

the region of an enzyme where the substrate binds and catalysis occurs

Where does a substrate bind on an enzyme?

active site

What binds to the active site of an enzyme?

substrate