MBB 231 Lecture 11: Metabolism

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pucecicada730

10 Mar 2017

School

Simon Fraser University

Department

Molec Biol & Biochem

Course

MBB 231

Professor

Stephanie Vlachos

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Document Summary

Atp: energy source of life: cells use energy from sunlight or food to make atp, cells convert external sources of energy into a biologically universal energy carrier adenosine triphosphate (atp) But it can be phosphorylated up to three times. Amp adp atp: hydrolysis of a high energy phosphoanhydride bond has a highly negative gibb"s free energy (-7. 3 kcal/mol). This means that the hydrolysis of atp to adp and pi is very exergonic. Atp can phosphorylate glucose but not pyruvate: the phosphate group is one of the most frequently transferred, especially in energy metabolism, called group transfer reactions. It is important that atp/adp occupy an intermediate position in terms of bond energy. 2- or pi: much of chemotrophic energy metabolism involves energy-yielding oxidative reactions (oxidation) In the cell, enzymes catalyze oxidation via a series of small steps in which free energy is transferred in small packets to carrier molecules (most often atp and nadh)

Related Questions

1.When something appears blue, it is absorbing all colors except__________.

yellow

blue

red

green

orange

2.During heavy exercise, lactic acid can build up in ourmuscles. Why? How does this resemble the metabolism of bacteria andyeast?

lactic acid is results from insufficient oxygen during sugarmetabolism; it is fermentation

lactic acid accumulates when we are dehydrated; bacteria andyeast use the same pathway

lactic acid is built up from carbon dioxide; bacteria and yeaststore energy in this way

3.Why must a cell keep a similar concentration of dissolvedsubstances with the fluid surrounding them?

to avoid dilution of potential energy

to avoid osmotic imbalance and rapid gain or loss of water

to maintain the correct amount of dehydration and hydrolysis

4.What is entropy?

the amount of energy in a system

the amount of disorganization

the amount of organization

5.Burning a log is the reverse reaction found in photosynthesis.What products would be formed in burning a log?

carbon dioxide and water

glucose and oxygen

oxygen and carbon dioxide

oxygen and water

6.The main reason that cellular respiration needs to occur stepby step instead of a single, big reaction is

cells don't store enough oxygen

too much energy would be released for the cell to harness

cells don't have many mitochondria.

cells produce the enzymes needed for cellular respiration veryslowly

7.Enzymes are catalysts because they operate to:

raise activation energy

lower activation energy

supply activation energy

supply the reactants

8.When ATP powers a reaction it becomes ADP. The ADP

can reform ATP by an exergonic reaction

is a waste product for lysosomal breakdown

can reform ATP by an endergonic reaction

can reform ATP by an oxidation reaction

can reform ATP by an equilibrium reaction

9.The energy source that drives photosynthesis is

water

glucose

carbon dioxide

oxygen

sunlight

10. What is the process by which enzymes regulate their ownactivity?

osmosis

self-propulsion

feedback inhibition

11.Coupled reactions are reactions in which a

endergonic reaction drives a spontaneous reaction

exergonic reaction drives a spontaneous reaction

endergonic reaction drives an exergonic reaction

exergonic reaction drives an endergonic reaction

12.How is water used in photosynthesis?

as a substrate for ATP synthase

as an electron donor

to combine with ADP forming ATP

as an electron acceptor

13.Why are the âDark Reactionsâ of photosynthesis referred to asâDarkâ?

they do not require light

they can only occur at night

they generate excess sugar and the leaves turn brown

14.What is the difference between potential and kineticenergy?

potential is stored, kinetic is being used

potential is being used, kinetic is ready to be used

potential is negative, kinetic is positive

15.The products of cellular respiration are

carbon dioxide, water, and ATP

glucose, water, and ATP

glucose, carbon dioxide, and ATP

oxygen, ATP, and water

carbon dioxide, glucose, and water

16.All of the following are correct about energy except:

The biological world gets its energy from the sun.

Chemical bonds store potential energy.

A boulder perched on a hill has kinetic energy.

Energy is defined as the ability to do work.

All forms of energy can be converted to heat.

17.What is needed for the end product of glycolysis, pyruvate,to enter the citric acid cycle?

More glucose for energy

ATP

Oxygen

Carbon dioxide

18.The enzyme that forms a transmembrane channel in mitochondriaand phosphorylates ADP

a carrier protein

ATP synthase

acetyl CoA

19.Fermentation is most common in

plants

microorganisms

animals

20.During adsorption of sunlight by photosystems, H+ ions aregenerated. Where do they come from? What are they used for?

from the breakdown of sugar; they help form water

water; they help form sugar

from carbon dioxide; they help dissolve NaCl

21.Glycolysis

does not use oxygen

uses oxygen

uses carbon dioxide

22.Photosynthesis is

not dependent on chlorophyll

a process that produces glucose and oxygen

a process that produces water and carbon dioxide

23.Breakdown of glucose generates many ATP molecules, each ofwhich can be used independently. Why is ATP ideally suited to powerbiological reactions?

ATP has many hydrogen bonds

ATP has enough energy to power one biological reaction

ATP readily dissolves in water

24.Objects that are not actively moving but have the capacity todo so are said to possess:

kinetic energy

entropy

potential energy

living energy

25.The first stage of cellular respiration, called ___________,takes place in the cytoplasm of the cell and needs no oxygen.

photorespiration

citric acid cycle

glycolysis

oxidation

26.Diffusion

requires energy

utilizes proteins to move molecules across a membrane

moves molecules against a concentration gradient

does not require energy

cannot occur without a membrane present

27.What is the name of the molecule on which an enzymeworks?

substrate

monomer

polymer

28.ATP contains

phenylalanine

two phosphate groups

three nitrate groups

three phosphate groups

29.How does chlorophyll function in photosynthesis?

by absorbing carbon dioxide

by absorbing the sun's energy

by absorbing water

30.Objects that are moving are said to possess:

living energy

potential energy

entropy

kinetic energy

31.The respiration pathway that evolved first is probably

glycolysis

aerobic respiration

citric acid cycle

32.The energy source for the process of photosynthesis is

oxygen

sunlight

carbon dioxide

chlorophyll

glucose

33.Burning wood generates heat and light. What type of reactionis this?

exergonic

kinetic energy

endergonic

potential energy

equilibrium

34.What is meant by a âcoupled reactionâ in terms of energy?

many poymers are built simultaneously

energy released by one reactions powers another reaction

some reactions occur in the same organelle

35.The First Law of Thermodynamics states:

energy is constantly being created by entropy events

energy can be changed from one form to another, but cannot becreated or destroyed

energy can be used and then destroyed because of entropy'sactions on it

energy can be destroyed while it is producing entropy

36.How do we dispose of the carbon derived from the glucose thatis metabolized during respiration?

by breathing out

via our urine

it is broken down in lysosomes

37.Both plant and animal cells have mitochondria because theyboth

carry on respiration

carry on photosynthesis.

require water

38.What is Activation Energy?

the energy needed to initiate a reaction

the energy that transports water into cells

potential energy

39.If you put a plant in a chamber and shine a light on it

oxygen will decrease and carbon dioxide will increase

oxygen will increase and carbon dioxide will decrease

oxygen and carbon dioxide will increase

oxygen and carbon dioxide will decrease

40.What are the inputs and the output molecules for the overallphotosynthetic process?

input sugar and oxygen; output carbon dioxide and water

input oxygen and water; output sugar and carbon dioxide

input carbon dioxide and water;output sugar and oxygen

41.What kind of reaction is photosynthesis?

endergonic

kinetic energy

exergonic

potential energy

equilibrium

42.In the process of glycolysis, glucose is cleaved into a pairof three-carbon molecules called

lactate

pyruvate

acetyl CoA

ATP

alcohol

43.Entropy is

order

disorder

complexity

Both order and disorder are correct

Both complexity and disorder are correct

44.Glycolysis takes place in the _____________ and the citricacid cycle and electron transport chain take place in the___________.

cytoplasm; endoplasmic reticulum

mitochondria, chloroplast

mitochondria; cytoplasm

cytoplasm; mitochondria

45.The organelle that carries out photosynthesis in plants isthe

mitochondria

chloroplast

ribosome

chlorophylllysosome

46.The energy to power the Calvin cycle comes from

cellular respiration

oxygen

the light reactions of photosynthesis

47.Which of the following can be broken down into intermediateproducts that enter cellular respiration?

Proteins

Lipids

Carbohydrates

All of these.

48.When cellular product levels get too high, the responsibleenzyme is inhibited. This is an example of

promotion

denaturation

equilibrium

a coenzyme

feedback inhibition

49.How is respiration the opposite of photosynthesis?

respiration breaks sugar down to carbon dioxide; photosynthesisbuilds sugar from carbon dioxide

respiration builds sugar from carbon dioxide; photosynthesisbreaks sugar down to carbon dioxide

respiration requires energy input; photosynthesis gives offexcess energy

50.The molecule that absorbs sunlight for photosynthesis is

oxygen

carbon dioxide

chlorophyll

glucose

sunlight

amaranthbear841

Value: 1

Anabolic pathways of metabolism are pathways that:

a. build complex molecules from simple ones.

b. release stored chemical energy.

c. take place primarily in skeletal muscle

d. make large quantities of ATP.

Value: 2

The sum of all chemical reactions in a cell is referred to as _______________.

Value: 3

Organisms that derive both their energy and carbon from organic compounds are:

a. photoautotrophs.

b. chemoautotrophs.

c. chemoheterotrophs.

d. photoheterotrophs

Value: 4

It is often stated that the phosphate bonds in ATP are "high energy," but in fact, they are not notably high in energy. Rather, they are easy to break, and the âG of hydrolysis is a "useful" quantity of energy. What makes the phosphate bonds easy to break?

a. They are close to the destabilizing nitrogenous base adenosine

b. Positive charges on amino groups repel each other.

c. Negative charges on phosphate groups repel each other

d. High acidity attacks bonds between amino acids.

Value: 5

Which of the following describes ATP hydrolysis? Select all that apply

[mark all correct answers]
a. exergonic

b. spontaneous

c. often coupled to a reaction that has a positive ÎG

Value: 6

Which of the following describes catabolic reactions?

a. They are endergonic and have a negative change in free energy

b. They are exergonic and have a negative change in free energy

c. They are exergonic and have a positive change in free energy.

d. They are endergonic and have a positive change in free energy.

Value: 7

Why are cells not infinitely big?

a. Because they wouldn't fit in an organism

b. Because they would have a small surface area:volume ratio and substances would diffuse in and out too slowly

c. Because they would have a large surface area to volume ratio and substances would diffuse in and out too quickly

Value: 9

How is organelle movement around cells controlled?

a. the nucleus directs the movement of organelles in a cell

b. the cytoskeleton is like a monorail that moves organelles in a cell via motor proteins

c. organelles do not move, they have a fixed position in the cell

d. organelles move by facilitated diffusion in the cell

Value: 10

1. Prokaryotic cells lack:

a. a. A nucleus

b. organelles

c. cell membrane

d. DNA

e. A and B

Value: 11

Rough endoplasmic reticulum (rER)

a. a. Makes cell membranes

b. has ribosomes attached

c. are a site of protein synthesis

d. all of the above

Value: 12

Match the items.

The task is to match the lettered items with the correct numbered items. Appearing below is a list of lettered items. Following that is a list of numbered items. Each numbered item is followed by a drop-down. Select the letter in the drop down that best matches the numbered item with the lettered alternatives.

a. help to digest worn-out or damaged organelles.
b. Takes in molecules in transport vesicles, modifies them, and sends them back out in vesicles
c. makes sugar
d. makes ATP
e. assembles the ribosomes
f. gives the cell structure
g. move material around the cell

1. vesicles	a b c d e f g
2. cytoskeleton	a b c d e f g
3. the golgi apparatus	a b c d e f g
4. lysosomes	a b c d e f g
5. mitochondrion	a b c d e f g
6. chloroplast	a b c d e f g
7. nucleolus

Which of the following is FALSE with respect to coupledreactions?

	they occur in ALL cells (bacteria, plants, animals, etc.)
	enzymes are typically involved
	endergonic reactions power exergonic reactions
	the coupled reaction has a ?G value that is negative
	none of the above (i.e., all of the above are TRUE)

Which of the following reactions is LEAST likely to bespontaneous? One with a:

	very large increase in entropy and a very large decrease inenthalpy
	very large increase in entropy and a very small increase inenthalpy
	very small decrease in entropy and a very large decrease inenthalpy
	very small increase in entropy and a very small decrease inenthalpy
	very small decrease in entropy and a very small increase inenthalpy

Energy of activation refers to the:

A)	?G of a reaction
B)	difference in energy between the transition state and theproduct
C)	difference in energy between substrate and product
D)	net change in free energy
E)	energy input needed to reach the transition state

Homeostasis refers to maintaining a relatively constantenvironment, and is achieved to a large extent by how enzymes areregulated. For example, when the end product of a pathway regulatesan enzyme that acts early in the same pathway, the effect is mostoften:

	stimulation if an anabolic pathway, and inhibition if acatabolic pathway
	inhibition if an anabolic pathway, and stimulation if acatabolic pathway
	stimulation, whether an anabolic or catabolic pathway
	inhibition, whether an anabolic or catabolic pathway

Enzymes function by:

	decreasing the free energy level of the reactants
	decreasing the free energy level of the transition state
	increasing the free energy level of the reactants
	changing delta G from positive to negative
	changing delta G from negative to positive
	increasing the free energy level of the products
	decreasing the free energy level of the products

6.	When carbohydrates are oxidized, the C

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MBB 231 Lecture 11: Metabolism

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