01:119:115 Lecture Notes - Lecture 5: Thermodynamics, Homeostasis, Exergonic Reaction

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10 Jan 2019

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Cell respiration: anabolic pathways, build complex molecule from simpler ones, use energy, ex. Synthesis of protein from amino acids: free-energy change in chemical reactions, energy= capacity to cause change/do work, kinetic energy, = e of motion, potential energy, = stored e has not yet been used. Total e available to do work decreases over time. Gibbs free energy (g)- the e available to do work +: more energy, -: energy came out. But: glucose + oxygen carbon dioxide + water + energy : can see how g changes during rx. G < 0 = energy is released from a reaction. Glucose + oxygen carbon dioxide + water + atp. G > 0 = energy is added to cause reactions, non-spontaneous. Cells use atp to carry energy: atp (adenosine triphosphate, spring loaded and high energy, 3 phosphate groups. Coupled reactions: pair exergonic reaction (provides e) with, endergonic reaction (requires e) Atp drives endergonic reactions by phosphorylation: passing up a phosphate group.

Related Questions

3) The hydrolysis of sucrose to glucose and fructose is exergonic. However, if you dissolve sucrose in water and keep the solution overnight at room temperature, there is no detectable conversion to glucose and fructose. Why?

Select one:

a. The change in free energy of the reaction is negative.

b. The activation energy of the reaction is high.

c. The free energy of the products is higher than the free energy of the reactants.

d. This is a condensation reaction.

e. The change in free energy of the reaction is positive.

5) Competitive inhibition differs from non-competitive inhibition in that the ___1___ site is where we see competitive inhibition, while the non-competitive inhibitor __2___.

1. a. allosteric b. non-active c. active d. hydrophillic e. hydrophobic

2.
a. binds to the active site, thus blocking it
b. binds outside the active site, changing the shape of the enzyme
c. binds outside the active site, and blocks the active site

6) Phosphofructokinase is an enzyme, and as such it __1___ of the reaction. It is part of glycolysis, and is an example of an enzyme controlled by inhibition, as high levels of citrate (an intermediate further down the catabolic pathway) turns the enzyme off
(1)Select one:
a. lowers activation energy
b. lowers the ÎG
c. raises the Free Energy
(2)Select one
a. non-competitivenegative feedback
b. irreversible competitivereversible competitive.

15)The reactions in the pathways of glycolysis and the citric acid cycle harvest the high-energy electrons stored in glucose. Therefore, these pathways _______________.

Select one:

a. take place in animal cells, but not in plant cells
b. are catabolic pathways
c. are anabolic pathways
d. involve the reduction of glucose and its metabolic intermediates

21) In an exergonic chemical reaction, the products have less free energy than the reactants (-ÎG). Endergonic reactions require an input of energy (+ÎG). The addition of starting materials and the removal of end products prevent metabolism from reaching final equilibrium. Instead, the cell exists in a state of dynamic equilibrium.

Select one:
True
False

greyferret515

Question 1 When energy changes from one form to another, some of the energy that can be used to do work is always lost. The loss of this energy is mostly in the form of _________.
a. heat
b. potential energy
c. kinetic energy
d. light energy
e. mechanical energy

Question 2 Which of the following is exergonic?
a. binding fatty acids and glycerol molecules together to form lipids
b. building proteins from amino acids
c. binding sugars molecules together to form glycogen
d. breaking bonds in starch to release glucose
e. adding a phosphate group to ADP to form ATP

Question 3 The first law of thermodynamics states that:
a. energy can neither be created nor destroyed.
b. the universe is increasing in entropy.
c. all living organisms must eat to derive energy.
d. energy is required to bring molecules into a cell against a concentration gradient.
e. in energy-yielding reactions, matter goes from a more-ordered to a less-ordered state.

Question 4 Which of the following is true of energy?
a. It can be transferred from one form to another with 100 percent efficiency.
b. It can be created.
c. It can be stored in chemical bonds.
d. It can never be stored.
e. It can be released by forming chemical bonds.

Question 5 Metabolism is:
a. the sum of all the energy a cell uses.
b. the sum of all the vitamins a cell contains.
c. the sum of all the enzymes a cell contains.
d. the sum of all the chemical reactions that an organism carries out.
e. the sum of all the ATP a cell contains.

Question 6 Entropy is the measure of ________ in a system.
a. disorder
b. order
c. energy
d. work
e. heat

Question 7 What percentage of the energy stored in glucose are humans cells able to use to do useful work?
a. 37%
b. 100%
c. 15%
d. 52%
e. 48%

Question 8 What is activation energy?
a. the energy gained by living things, allowing them to remain active
b. the energy produced by the breakdown of ATP to ADP.
c. the energy required to initiate or begin a chemical reaction
d. the energy created by enzymes during exergonic reactions
e. the energy lost by living things in the form of heat

Question 9 Which of the following is true of allosteric enzymes?
a. Their activity can be reduced when the product binds the enzyme.
b. Their activity can be reduced when a coenzyme binds to them.
c. Their activity can be reduced when the substrate binds the enzyme.
d. Their activity can be increased when the product binds the enzyme.

Question 10 Which of the following is a true statement about enzymes?
a. They are made of proteins.
b. They are altered by the reactions they catalyze.
c. They increase the energy of activation of chemical reactions.
d. All of the above are true.
e. None of the above is true.

Question 11 What is the energy currency of cells?
a. ADP
b. enzymes
c. glucose
d. vitamins
e. ATP

Question 12 Kinetic energy is ____________, while potential energy is _____________.
a. stored energy; energy that is being used
b. stored energy; energy that can't be used
c. energy that is being used; stored energy
d. energy that can't be used; stored energy

Question 13 The energy released during ________ reactions can be used to drive ________ reactions, and this is called ________ reactions.
a. exergonic; endergonic; coupled
b. endergonic; exergonic; coupled
c. exergonic; endergonic; mutually dependent
d. coupled; mutually dependent; independent
e. endergonic; exergonic; mutually dependent

Question 14 ADP + P + Energy --> ATP Which of the following is a true statement about the chemical reaction above?
a. This is a coupled reaction.
b. This is an exergonic reaction.
c. The product of the reaction contains more energy than that of all of the reactants combined.
d. This is an endergonic reaction.
e. This is an example of a catabolic reaction.

greychimpanzee211

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

01:119:115 Lecture Notes - Lecture 5: Thermodynamics, Homeostasis, Exergonic Reaction

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