Bio exam 2

3 forms of energy

mechanical, light, chemical

is chemical energy kinetic or potential

potential

where is chemical energy stored?

in the bonds

if shared electrons are far from the nucleus, bonds are (short/long) and (weak/strong). they have (high/low) potential energy.

long; weak; high

when electrons are shifted closer to the n nucleus, bonds become (longer/shorter) and (stronger/weaker). they have (higher/lower) potential energy

shorter; stronger; lower

is this the first or second law of thermodynamics:

energy can be transferred and transformed, but it cannot be created or destroyed. energy is conserved.

first law of thermodynamics

is this the first or second law of thermodynamics:

during every energy transfer or transformation, some energy is unusable, and is often “dissipated” as heat. total entropy always increases in a system that includes the surroundings as wells as the products of the reaction.

second law of thermodynamics

measure of randomness or disorder within a system

entropy

high entropy means (high/low) disorder and (high/low) energy

high; low

low entropy means (high/low) order and (high/low) energy

high; high

number of states a system can take on

disorder

when a reaction generates more disorder, entropy (increases/decreases)

increases

total heat energy of a system at constant pressure

enthalpy (H)

is energy of the movement of the molecules within a system entropy or enthalpy?

enthalpy

is potential energy in bonds of molecules entropy or enthalpy

enthalpy

energy needed to occupy space

(PV)

symbol for changes in enthalpy

delta H

does entropy or enthalpy tells us whether a reaction gives heat away or needs heat to happen

enthalpy i

if delta H < 0 is it endothermic or exothermic

exothermic

if delta H > 0 is it endothermic or exothermic

endothermic

changes in enthalpy are primarily based on difference in (kinetic/potential) energy

potential

do endothermic or exothermic reactions release heat

exothermic

do endothermic or exothermic reactions have a negative delta H

exothermic

do endothermic or exothermic reactions have products with less potential energy than reactants

exothermic

do endothermic or exothermic reactions have heat energy that is taken up during the reaction

endothermic

do endothermic or exothermic reactions have a positive delta H

endothermic

do endothermic or exothermic reactions have products with higher potential energy than reactants

endothermic

delta G = delta H - T(delta S) is the equation for what

Gibbs free energy (G) (standard free energy change equation)

---

___determines whether reaction is spontaneous or requires added energy to proceed (non-spontaneous)

Gibbs free energy

(spontaneous/non-spontaneous) reactions require added energy to proceed

non-spontaneous

what is the symbol for change in enthalpy

delta H

what is the symbol for change in entropy

delta S

what is the symbol for temperature in degrees Kelvin

T

if a chemical reaction requires an input of energy, then (delta G > 0/ delta G < 0)

delta G > 0

___ reactions have products with more free energy than their substrates

endergonic

if energy is released in a chemical reaction than (delta G > 0/ delta G < 0)

delta G < 0

products of (endergonic/exergonic) reactions will have less free energy than the substrates

exergonic

exergonic reactions are (spontaneous/non-spontaneous) because they occur (with/without) the addition of energy

spontaneous; without

the initial energy needed to start a chemical reaction is called ___

activation energy (E A)

in a diagram the hump is considered the ___

activation energy

activation energy causes reactants to become (stable/unstable), which allows bonds to be broken or made.

unstable

the ___ state is when a reaction is unstable after the activation energy hump

transition

once in the transition state, a reaction occurs very (slowly/quickly)

quickly

__ energy is the main source fro activation energy in a cell

heat

__ helps reactions reach their transition state

heat

chemical reaction proceed in a direction that results in : (higher/lower) potential energy, (increased/decreased) entropy, or both

lower; increased

enzymes (slow down/speed up) metabolic reactions by lowering energy barriers

speed up

__ energy is the initial energy needed to start a chemical reaction

activation

a __ is a catalytic protein

enzyme

a __ is a chemical agent that speeds up a reaction without being consumed by the reaction.

catalyst

enzymes (higher/lower) activation energy for a reaction

lower

do enzymes affect the change in free energy (delta G)??

no.

what kind of bond is between an enzyme and its substrate

covalent

an enzyme will (always/never) return to its original state by the completion of the reaction

always

____ are inorganic ions that reversibly interact with enzymes

cofactors

____ are inorganic molecules such as NADH or FADH with enzymes

coenzymes

____ are non-amino acid atoms or molecules permanently attached to proteins

prosthetic groups

true or false:

reaction rates level off because all available enzyme molecules are being used

true

which of the following cause the activity of an enzyme to change:

• temperature

• pH

• modifications of primary structure

• interactions with other molecules

all of the above

____ is when molecules binds actives site of an enzyme competing with the substrate

competitive inhibition

____ is when molecules bind to another part of an enzyme, causing the enzyme to change shape and making the active site less effective.

allosteric regulation

____ can either inhibit or stimulate an enzymes activity

allosteric regulation

___ are a series of ordered reactions that build p or break down a molecule

metabolic pathways

____ are each catalyzed by a different enzyme

metabolic pathways

as concentration of product becomes abundant it “feeds back” to (continue/stop) the reaction

stop

as concentration of product becomes abundant, amount of initial substrate (is/is not) depleted

is not

as concentration of product becomes abundant it is stored or used for other reaction, true or false?

true

____ is the repetition of backward process produces multistep metabolic pathway

retro-evolution

____ is when new enzymes are recruited to new pathways

patchwork evolution

___: all organisms consist of cells

cell theory

what are the 4 things that all cells have?

plasma membrane, cytoplasm, ribosomes (proteins), and nucleic acids

____ serves as a selectively permeable membrane barrier

plasma membrane

____: cytosol in which other components of the cell are found

cytoplasm

____: perform most of the cell’s functions

ribosomes - proteins

____: store, transmit, and process information

nucleic acids

(prokaryotes/eukaryotes) have membrane bound nucleus

eukaryotes

(prokaryotes/eukaryotes) lack membrane-bound nucleus

prokaryotes

bacteria is (prokaryotic/eukaryotic)

prokaryotic

archaea is (prokaryotic/eukaryotic)

prokaryotic

eukarya is (prokaryotic/eukaryotic)

eukaryotic

(prokaryotic/eukaryotic) cells are smaller than (prokaryotic/eukaryotic) cells

prokaryotic; eukaryotic

____ lack membrane-enclosed internal compartments

prokaryotes

____ contain at least one chromosome (DNA)

prokaryotes

____: cell membrane I surrounded by a cell wall

prokaryotes

____: consist of fatty acid bound to glycerol

bacterial phospholipids

____: used to branched isoprenoid chains bound to glycerol

archaeal phospholipids

____: all contents of cell inside membrane

cytoplasm

____: fluid portion of cell

cytosol

• most bacterial and Racheal species have single circular ___

• prokaryotic cells may contain circular, supercoiled DNA molecules called plasmids

chromosome

DNA molecule with proteins

chromosome

circular, supercoiled DNA molecules

plasmids

• RNA molecules and protein

• used for protein synthesis

• ___ in bacteria and archaea similar in size and function

ribosomes

long, thin protein filaments in cytoplasm

cytoskeleton

___ and ___ contain a cytoskeleton

bacteria; archaea

• in bacteria, essential for cell division

• maintains cell shape

cytoskeleton

• develop as infolding of plasma membrane

• contain enzymes and pigment molecules required fro reactions to occur

internal photosynthetic membranes

are these internal or external structures of a prokaryotic cell?

• flagella

• fimbriae

external

___: structures found on bacterial surfaces

flagella and fimriae

___: long filaments that rotate to propel cell

flagella

___: needlelike projections that promote attachment to other cells or surfaces

fimbriae