BIO 141 Exam 2 - ch 22,6,7,8,9 - all cards

entropy of the universe

Whenever energy is transformed there is always an increase in the _____.

delta G is less than zero

An endergonic reaction has all the following characteristics, except

	a)  the reaction is non-spontaneous
	b)  Delta G (Gibb's free energy) is less than zero (a negative value)
	c)  enzymes are needed to make the reaction occur in a timely manner
	d)  energy is needed to make the reaction occur

thermal energy

Which of the following forms of energy is least available to accomplish cellular work?

a)  mechanical energy

b)  electrical energy

c)  potential energy

d)  light energy

e)  thermal energy (heat)

energy cant be created or destroyed

Which of the following statements best describes the first law of thermodynamics?

a)  Energy cannot be transferred or transformed.

b)  Energy cannot be created or destroyed.

c)  The entropy of the universe is constant.

d)  The entropy of the universe is decreasing.

G is the change in free energy

The mathematical expression for the change in free energy of a system is ΔG = ΔH - TΔS. Which of the following statements best describes a term in this equation?

a)  ΔH is the change in entropy, the energy available to do work.

b)  ΔS is the change in enthalpy, a measure of randomness.

c)  T is the temperature in degrees Celsius.

d)  ΔG is the change in free energy

endergonic

Which of the following terms best describes a chemical reaction for which ΔG is positive?

a)  spontaneous

b)  endergonic

c)  exergonic

d)  enthalpic

Which of the following statements best describes a system at chemical equilibrium?

a)  The system can do no work.

b)  The system consumes energy at a steady rate.

c)  The system releases energy at a steady rate.

d)  The kinetic energy of the system is zero.

hydrolysis reactions are exergonic and increase entropy of the system

Which of the following statements best describes why hydrolysis reactions occur more readily in solution than dehydration reactions do?

a)  Hydrolysis reactions increase G, or Gibbs free energy of the system.

b)  Hydrolysis reactions are exergonic and increase entropy of the system.

c)  Hydrolysis reactions are endergonic and increase entropy of the system.

d)  Hydrolysis reactions are exergonic and decrease entropy of the system.

ATP produces energy coupling between exergonic and endergonic reactions

Which of the following statements best describes the central role that ATP plays in cellular metabolism?

a)  The terminal phosphate bond is stronger than most covalent bonds in other biological macromolecules.

b)  Hydrolysis of ATP provides an input of free energy for exergonic reactions.

c)  Hydrolysis of the terminal phosphate group from ATP stores free energy that is used for cellular work.

d)  ATP provides energy coupling between exergonic and endergonic reactions.

the released phosphate is used to form propylated intermediates that are more reactive than the original unphosphorylated substrate

Which of the following statements best describes a primary mechanism by which the energy released in ATP hydrolysis is used directly to drive endergonic chemical reactions in a cell?

a)  Free energy is released as heat, which speeds up the rate of endergonic reactions.

b)  Binding of ATP to an enzyme active site converts an endergonic reaction to an exergonic reaction.

c)  The released phosphate is used to form phosphorylated intermediates that are more reactive than the original unphosphorylated substrate.

d)  The phosphate is combined with ADP to regenerate ATP.

binding of substrate to the active sit changes the shape of the active site of an enzyme

Which of the following statements best describes induced fit?

a)  Substrate binds to an allosteric site rather than to the active site of an enzyme.

b)  Binding of an activator molecule changes the shape of the active site of an enzyme.

c)  The conformation of the active site is determined by the tertiary or quaternary structure of the enzyme.

d)  Binding of substrate to the active site changes the shape of the active site of an enzyme.

the catalyzed reaction will have the same G as the uncatalyzed reaction

Which of the following statements best describes how addition of a catalyst will affect a chemical reaction?

a)  The catalyzed reaction will have the same ∆G as the uncatalyzed reaction.

b)  The catalyzed reaction will have a lower ∆G than the uncatalyzed reaction.

c)  The catalyzed reaction will consume all of the catalyst.

d)  The catalyzed reaction will have a higher ∆G than the uncatalyzed reaction

by changing the 3-D shape of the enzyme

A change of a single amino acid at a position distant from the active site of an enzyme can alter the substrate specificity by changing the ________.

a)  by changing the stability the enzyme

b)  by changing the intracellular location of the enzyme

c)  by changing the binding site for a competitive inhibitor

d)  by changing the 3-D shape of the enzyme

temperature is usually uniform throughout a cell

Most cells cannot harness heat to perform work because

a)  heat can never be used to do work.

b)  heat does not involve a transfer of energy.

c)  cells do not have much thermal energy; they are relatively cool.

d)  temperature is usually uniform throughout a cell.

proteins and phospholipids

Choose the best answer. Cellular membranes are made of _______________.

a)  phospholipids only

b)  protein only

c)  proteins and phospholipids

d)  cholesterol only

sodium will move to the inside

If sodium is in higher concentration on the outside of a cell relative to inside the cell, which direction will sodium move if there is an open channel that allows sodium to cross the membrane.

the cell becomes lysed

If an animal cell is placed into a hypotonic solution what will occur? 

a)  cell becomes flaccid

b)  cell becomes plasmalyzed

c)  cell becomes lysed

d)  cell becomes turgid

passive and uses a channel

A process that used facilitated diffusion is best described by which of the following?

a)  passive and uses a channel

b)  passive and direct across the membrane

c)  active and uses a channel

d)  active and direct across the membrane

rough ER, cytoplasm, mitochondria

where are ribosomes present in the cell

Eukaryotic cells have membrane-bound organelles, while prokaryotic cells do not.

What best describes one major difference between prokaryotic cells and eukaryotic cells?

digestive enzymes

Lysosomes generally have ______________ in them.

active transport

The movement of a substance across the membrane against its concentration gradient with the help of energy input is _________.

facilitated diffusion

Water moves through cellular membranes by which of the following ways?

a)  facilitated diffusion

b)  active transport

c)  exocytosis

lamark

The first publication on evolution was written by ____________.

paleontology

The study of fossils is called ______________.

natural selection

What is the mechanism that Darwin described as the mechanism for  evolution?

catastrophism

What term described that natural disasters led to the extinction of species?

a)  Uniformtarisnism

b)  Natural selection

c)  Catastrophism

d)  Gradualism

long pointed beak

Which of the following might be an adaptation to picking insects out of the bark of a tree?

a)  Webbed feet

b)  Long pointed beak

c)  Strong claws

d)  A string thick beak

radiometric dating of fossils

Which of the following was not used as support for evolution and natural selecton during Dawrwin's time (mid 1800's)?

a)  biogeography

b)  gradual changes leading to geological changes in rock formation

c)  paleontology finds

d)  radiometric dating of fossils

entropy of the universe

Whenever energy is transformed there is always an increase in the _____.

a)  entropy of the universe

b)  free energy of the universe

c)  free energy of the system

d)  enthalpy of the universe

metabolism consists of all the energy transformation reactions in an organism

Which of the following statements best describes metabolism in its entirety in all organisms?

a)  Metabolism uses all of an organism's resources.

b)  Metabolism depends on a constant supply of energy from food.

c)  Metabolism consists of all the energy transformation reactions in an organism.

d)  Metabolism manages the increase of entropy in an organism.

catabolism

Which of the following terms most precisely identifies the cellular process of breaking down large molecules into smaller ones?

a)   catabolism (catabolic pathways)

b)  dehydration

c)  anabolism (anabolic pathways)

d)  metabolism

1. cell to cell communication

2. enzymatic activity

3. transport across membrane

what are the functions of proteins in the membrane [3]

diffusion

Oxygen travels through the membrane by ____________

active transport

Transporting Na+ ions out of most cells is done through ______

diffusion

Lipids can enter cells by ______________ process.

site of protein synthesis

what is the main function of a ribosome

• semi permeable, some things get through some don’t, it protects the cell because of its control. allows for the storage of energy by moving things from one side to the other - transfer of energy

• allows for molecules [enzymes, cytochromes] to be close to each other

• phospholipids - polar and non polar

membrane

• function

• importance of location

• what’s it made of

have a hydrophilic head [outside] and hydro phobic tail [inside]

they are arranged in a bilayer with the phillic heads facing out and the phobic heads on the inside

Describe the properties of phospholipids and their arrangement in cellular membranes.

they split the membrane down the middle of the phospholipid bilayer and are proteins embedded directly within the core of the membrane rather than just sitting of the surface

Explain what freeze-fracture techniques reveal about the involvement of proteins in membranes.

fluid properties have more spacing between the hydrophilic heads

they have unsaturated hydrocarbon tails -double bonds

this makes it easier for things to pass through the membrane

Describe the fluid properties of the cell membrane and explain how membrane fluidity is influenced by membrane composition.

carbohydrates are located exclusively on the extracellular side

Describe how proteins and carbohydrates are spatially arranged in cell membranes and how they contribute to membrane function.

concentration gradients - molecules want to move from high to low concentrations

• ex. more Na is outside the cell so they will go in and more K is in the cell so they will go out

transport proteins regulate what can go in and out of the cell

protein channels are specific to what ions can pass through

Describe factors that affect the selective permeability of membranes.

they are located spanning across the membrane

• integral proteins span across the membrane or peripheral proteins attach to the surface

they function as channels or carriers to help specific molecules, ions, and water cross the hydrophobic barrier

Describe the locations and functions of transport proteins.

it is the movement of particles from a high concentration to low

takes no energy

the driving force is the concentration gradient

Define diffusion. Explain what is the driving force behind diffusion.

it is regulated by the concentration gradient

have channels specific to what can pass through

it is basically diffusion with some help

no energy

Explain what regulates the rate of passive transport.

molecules naturally store energy when moved by a concentration, which is released as they flow down their gradient to perform work

Explain why a concentration gradient across a membrane represents potential energy.

hypotonic

• animal = lysed - over filled

• plant = turgid - normal

• more water less solute inside cell

isotonic

• animal = normal

• plant = flaccid - under filled

hypertonic

• animal = shriveled

• plant - plasmolyzed

• more solute less water inside cell

Distinguish between hypertonic, hypotonic, and isotonic solutions.

its the diffusion of water across a selectively permiable membrane

water moves from an area of lower solute concentration [higher water] to an area of higher solute concentration [ lower water ]

Define osmosis and predict the direction of water movement based on differences in solute concentrations.

They go across the membrane

take a certain amount of proteins across and need ATP to be phosphorylated in order to change cell shape and move contents across membrane.

Explain how transport proteins are structurally organized.

facilitated is like diffusion with some help

the ions are still moving with their concentration gradient - so its passive

the channel is specific to what can pass through

some are carrier proteins that change their shape to help the movement of a solute

[there are two types a channel type and a switch type]

Explain how transport proteins facilitate diffusion.

it requires energy because it moves substances against their concentration gradient

when ATP comes along it phosphorylates the protein - allowing it to shift

when K comes the protein dephosphorylates

• for example the Na/K pump when Na attaches to the protein ATP phosphorylates, attaching a P to the protein and giving it the energy to shift and release the Na to the other side.

• then K comes and attached to the pump, it can use the P again to drive the K into the cell then

Explain how active transport differs from diffusion

ion pumps [like the Na / K pump or proton pump] use ATP to actively transport ions across the membrane against their gradient, creating unequal distribution of charge and concentration

Explain what mechanism can generate a membrane potential or electrochemical gradient

in a proton pump energy is needed to get H from inside the cell [in tje cytoplasm] to outside the cell [extracellular]

once the H build up it can diffuse back into the cell and sucruse can use the H to move with it

it is using an exergonic motion to drive and endergonic

Describe the process of co-transport

dont

• diffusion

• facilitated diffusion

do

• active transport

• endo/exocytosis

what membrane processes need energy vs which dont

1. facilitated diffusion

2. diffusion

3. .

4. diffusion

5. aquaporins

6. facilitated diffusion

how do each of these move through proteins - what method of travel

1. carb

2. lipid

3. protein

4. gasses

5. water

6. ions

1. cell membrane made of phospholipids and has proteins

2. regulates things that go in and out of the cell

   1. polar, hydrophobic tail

   2. nonpolar, hydrophilic head

plasma membrane

• location

• function

1. mid cell

2. DNA, genetic information

   1. nucleolus - where RNA is produced

   2. chromatin - DNA and protein

nucleus

• location

• function

1. cytosol, rough ER, mitochondria

2. protein synthesis

ribosome

• location

• function

1. many in cell - number depends of cell needs

• fat cells dont have a lot but muscle cells have a lot

2. where ATP is produced

mitochondria

• location

• function

1. cytoplasm

2. folding proteins

Rough ER

• location

• function

1. cytoplasm, near nucleus

2. makes lipids, detoxifies, store calcium

   1. no ribosomes

smooth ER

• location

• function

1. near nucleus, SER, RER

2. modifies molecules by target and addresses them so they can be sent to the right target

golgi apparatus

• location

• function

1. cytoplasm

2. breakdown waste, they store stuff, break fown macromolecules into single monomers

lysome

• location

• function

their membrane is able to fuse with other membranes and carry things around the cell

vesicles and vacuole

• function

1. microtubules, intermediate filaments, micro filaments

2. all over cell

3. organize, internal transport, shape of cell

cytoskeleton

• 3 types

• location

• function

catabolic breaks down complex molecules into simpler compounds

• RELEASE energy

anabolic consume energy to build complex molecules from simpler ones.

• NEED energy

Explain the difference between catabolic and anabolic reactions

the study of how energy flows through living organisms

What is bioenergetics

1. energy can be transferred and transformed but it cannot be created or destroyed

2. every energy transfer or transformation some energy is unusable and is often lost as heat

   1. heat cant do any work

   2. every energy transfer / transformation increases the entropy of the universe

Explain the two laws of thermodynamics in relation to biology

kinetic is energy associated with motion

potential is energy that matter posses because of its location or structure

Describe the two types of energy, potential and kinetic

spontaneous occurs

• without energy input - can happen quickly or slowly

nonspontaneous

• needs an input of energy - decrease entropy

Describe the differences between spontaneous reactions and non-spontaneous reaction

free energy is energy that can do work when temperature and pressure are uniform - its the amount of energy a cell can use

gibbs energy = H -TS

G = total energy - unusable energy

G is positive for nonspontaneous - needs energy - endergonic

G is negative for spontaneous - release energy - exergonic

more stable at low G less stable at high G

free energy

• describe

• equation

• pos vs neg / ender vs exergonic

• stable vs unstable

equilibrium is reached when forward and reverse reactions are occurring at the same rate - no work is being done

cells are constantly out of equilibrium due to the constant flow of materials in and out - they are always doing work

• multiple stages of energy, each giving some power at each stage

Explain what is meant by a metabolic dis-equilibrium that is needed to maintain life

• what is happening at equilibrium

• why are cells in dis-equilibrium

energy coupling is the use of an exergonic process to drive an endergonic one.

• most energy coupling in cells is mediated by ATP

ATP releases more energy with the loss of a phosphate than most other molecules could deliver

ATP breaks down and loses one phosphate group and becomes ADP. this releases energy. the phosphate is then transferred to another molecule, making it more reactive or easier to change.

Describe how ATP powers cellular work by coupling exergonic reactions to endergonic reactions through phosphorylation. What is phosphorylation

• hydrolysis of ATP

The transition state is the level a molecule needs to get to to start the reaction

enzymes help the reactant go through its reaction by lowering its activation energy

once enzymes bind to a substrate the active site becomes unstable and the Ea is lowered, allowing for the reaction to speed up

after that the substrate becomes a product and the product is released

Describe the importance of enzymes to living system

• transition state

• activation energy

• binding

• product

The substrate is a molecule the enzyme acts on

once binded to the substrate it forms a enzyme-substrate complex

the active site the area of the enzyme where the substrate can bind

an induced fit brings chemical groups to the active site into positions that enhance their ability to catalyze the reaction. - the enzyme will change its shape to best fit the substrate

Explain how enzymes work

• substrate

• complex

• active site

• induced fit

an inhibited can black the substrate from entering the active site

• completive inhibition - there is a lot of the inhibiter present and it competes with the substrate to bind to an enzyme

• noncompetitive alters / changes the binding site so the substrate is unable to attach. only once the non competitive inhibiter leaves can the substrate bind

allosteric regulation is similar to noncompetitive

• when an activator binds - the substrate is able to bind

• but when the inhibiter the substrate is unable to bind - it makes the cell inactive

feedback inhibition

• the product of an activated substrate becomes an inhibiter

• this process doesn’t make waste project - it repurposes product

Explain how enzymes are regulated by several different mechanism

• competitive

• noncompetitive

• allosteric

• feedback

endergonic

• energy needed

• nonspontaneous

exergonic

• energy released

• spontaneous

endergonic vs exergonic reaction

• energy

• spontaneous vs non

exergonic

• reactions due to their chemical structure have more energy than their products

• through the progress of the reaction energy is released and G is smaller no energy input - this reaction is spontaneous

endergonic

• when reactants energy is lower than the product the only way to get there is with the addition of energy

• Gibbs goes up energy is added - the reaction is non spontaneous

explain this figure

• free energy changes exergonic and endergonic reactions

1. adding ammonia to the acid converts it to glutamine

   1. gibbs is positive = no energy added = nonspontaneous

2. Or you can phosphorilize ATP = attaching a phosphate to the glutamic acid and making the reactant Phosphorylated intermediate plus with P plus ADP = ammonia can be added during the reaction making the product glutamine plus ADP plus P

3. The coupled reaction

   1. reactants are glutamic acid plus ammonia plus ATP = glutamine plus ADP plus P

   2. they net G is negative = nonspontaneous

explain how hydrolysis of ATP drives chemical work when involving glutamic acid

• 2 ways

• what’s the coupled reaction

ATP = ADP plus P

this process can be repeated through catabolism and cellular work

when ATP is used for a reaction what is it concerted to

Both catabolic [break down] pathway of making ATP

Fermentation

• its a partial degradation of sugars that occurs without oxygen

Cellular respiration

• includes both aerobic and anaerobic respiration

• the break down of glucose and other organic molecules to produce ATP

• aerobic respiration yields significantly more ATP using an ETC and oxygen as the final electron acceptor.

Distinguish between fermentation and cellular respiration.

• what is the reactants and products of glucose

glucose + oxygen = CO2 + water + ATP [heat]

when oxygen is added to glucose it is able to break down. its products are CO2, water, ATP, and heat

Glucose releases energy when its bonds are broken.

Describe the summary equation for cellular respiration.

Also note the specific chemical equation for the degradation of glucose

ATP can go through hydrolysis [add water] and break down to ADP plus P

and go through cellular processes to regenerate ATP

Explain how ATP is recycled in cells.

loss of electrons = oxidation

addition of electrons = reduction

oxidation-reduction reactions = redox

Define oxidation and reduction

define redox reaction

glucose and other organic molecules are oxidized in a series of steps

each electron travels with a proton - thus as a hydrogen atom

hydrogen atoms are usually first passed to electron carriers than directly to O2

Explain why organic molecules that have an abundance of hydrogen are excellent cellular fuels.

NADplus can be reduced into NADH.

ETC accepts electrons from NADH and FADH2 and passes them through a series of protein complexes to lower energy states [ to cytochromes], ultimitly reaching oxygen. this electron flow powers the pumping of protons to establish a proton gradient

Describe the role of NAD+ and the electron transport chain during respiration

glycolysis - cytoplasm

krebs - mitochondrial matrix

ETC - inner membrane of mitochondrion

Describe the cellular regions where glycolysis, the Krebs cycle, and the electron transport chain occur

ATP is needed to break down glucose into 2 pyruvates - which starts the glycolysis stage

Explain why ATP is required for the preparatory steps of glycolysis

in glycolysis

• the oxidation and reduction of NADplus to NADH occur during their energy payoff phase

• substrate phosphorylation also occurs in the payoff phase when enzymes transfer phosphate groups directly from ADP to ADP

pyruvate to acetyl CoA

• pyruvate is oxidized as it enters into the mitochondrial matrix, producing CO2, NADH, and acetyl CoA

Krebs link

• the transition converts the end product of glycolysis - pyruvate - into acetyl CoA, which the directly enters and dives the krebs cycle

Identify where sugar oxidation, substrate-level phosphorylation, and the reduction of NAD+ occur in glycolysis,

where pyruvate is oxidized to acetyl CoA,

what molecules are produced,

and how this process links glycolysis to the Krebs cycle

as electrons exergonically move doen the ETC free energy is released and used by protein complexes to pump protons [H] across the membrane.

this creates a proton gradident that couples the rel

Explain how the exergonic "slide" of electrons down the electron transport chain is coupled to the endergonic production of ATP by chemiosmosis

chemiosmosis is the process where protons flow down their concentration gradient back into the mitochondrial matrix using ATP synthase.

the flow of protons turns the ADP back into ATP

Describe the process of chemiosmosis

protein

• broken down into amino acids, remove amino groups as NH3, enter glycolysis, pyruvate oxidation, or CAC

carb

• concerted into sugars that feed directly into glycolysis

fat

• broken down into glycerol - which can enter glycolysis - and fatty acids - which can be broken down into acetyl CoA and enter CAC

Describe how food molecules other than glucose can be oxidized to make ATP

ATP is controlled via feedback regulation

PFK is an allosteric enzyme that acts as the pacemaker of glycolysis

where there is an abundance of ATP it can inhibit PFK by binding to it. when this happens glycolysis and cellular respiration is slowed

once ATP levels drop the inhibition is lifted and the cycle can continue

Explain how ATP production is controlled by the cell and what role the allosteric enzyme, phosphofructokinase [PFK], plays in the process

stage - 1 - glycolysis

location - cytoplasm

energy in - glucose bonds, 2ATP [ a little ATP]

energy out - 2 pyruvate bonds, NADH, ATP

brief description- glucose is stable and something has to destabilize it. adding ATP adding phosphate destabilizes it and breaks it down enough to make energy. it is a rearrangement of molecules [carbons] - which releases a little bit of NADH, and a little ATP then your up to pyruvate

Glycolysis

• stage

• location

• energy in

• energy out

• brief description