01:119:115 Lecture Notes - Lecture 8: Chemical Energy, Kinetic Energy, Metabolic Pathway

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rubysalmon273

15 Feb 2018

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The energy transformations of life are subject to two laws of thermodynamics: thermodynamics is the study of energy transformations. In this field, the term system refers to the matter under study and the surroundings include everything outside the system: a closed system, approximated by liquid in a thermos, is isolated from its surroundings. Some are very slow, such as the rusting of an old car: another way to state the second law of thermodynamics is for a process to occur spontaneously, it must increase the entropy of the universe. O(cid:373)e (cid:396)e(cid:448)e(cid:396)si(cid:271)le (cid:396)ea(cid:272)tio(cid:374)s of (cid:396)espi(cid:396)atio(cid:374) a(cid:396)e (cid:272)o(cid:374)sta(cid:374)tl(cid:455) (cid:862)pulled(cid:863) i(cid:374) o(cid:374)e di(cid:396)e(cid:272)tio(cid:374), as the p(cid:396)odu(cid:272)t of one reaction does not accumulate but becomes the reactant in the next step. Sunlight provides a daily source of free energy for photosynthetic organisms: nonphotosynthetic organisms depend on a transfer of free energy from photosynthetic organisms in the form of organic molecules. Concept 8. 4 enzymes speed up metabolic reactions by lowering energy barriers.

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

The complete set of reactions carried out by an organism is called:

a. anabolism

b. catabolism

c. metabolism

Value: 2

The breakdown of starch is broken down to glucose is an example of:

a. anabolism

b. catabolism

c. metabolism

Value: 3

For the following statement, determine which description best describes the process: DNA is synthesized from free nucleotides.

a. anabolism

b. catabolism

c. metabolism

Value: 4

Fill in the blank: Catabolic reactions result in the synthesis of molecules of .............via cellular respiration. This is then used to power anabolic reactions.

Value: 5

The energy in organic molecules is released in a series of steps because:

a. it is not possible to release it in a single step.

b. more total energy is released in multiple steps than would be released in a single step

c. less total energy is released in multiple steps than would be released in a single step.

d. more energy can be harvested for cellular use in multiple steps than from a single step.

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photosynthesis

1-The light reaction of photosynthesis does not include

a. chemiosmosis

b. oxygen liberation

c. glucose synthesis

d. electron transport

Value: 2

Photosynthesis takes place in the membranes of small sacs called

a. thylakoids

b. photosystems

c. stroma

d. photons

Value: 3

During what stage of photosynthesis is O2 produced?

a. the light-dependent reactions involving photosystems I and II

b. carbon fixation

c. the Krebs cycle

d. O2 is not produced during photosynthesis

Value: 4

The pigment molecules responsible for photosynthesis are located in the

a. mitochondria

b. cytoplasm of the cell

c. stroma of the chloroplast

d. thylakoid membrane of the chloroplast

Value: 5

During what stage of photosynthesis are ATP and NADPH converted to ADP + Pi and NADP+?

a. the light-dependent reactions

b. the light-independent reactions

c. both of the above

d. none of the above

Value: 6

What energy-rich organic compound is produced as a result of the Calvin cycle?

a. ATP

b. NADPH

c. glucose

d. H2O

Value: 7

During photosynthesis, photons raise electrons to higher energy levels. These excited electrons belong to what compound?

a. water

b. ATP

c. chlorophyll

d. electron transport chain

Value: 8

Which of the following statements accurately describes the relationship between photosynthesis and cellular respiration?

a. photosynthesis occurs only in autotrophs; cellular respiration occurs only in heterotrophs

b. photosynthesis uses solar energy to convert inorganics to energy-rich organics; respiration breaks down energy-rich organics to synthesize ATP

c. photosynthesis involves the oxidation of glucose; respiration involves the reduction of CO2

d. the primary function of photosynthesis is to use solar energy to synthesize ATP; the primary function of cellular respiration is to break down ATP and release energy

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 8: Chemical Energy, Kinetic Energy, Metabolic Pathway

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