Cellular Metabolism

Question 1

What is the first law of thermodynamics?

Answer 1

Energy can’t be created nor destroyed and can only be transformed form one form to another

Question 2

What is the second law of thermodynamics?

Answer 2

Closed system moves towards increased disorder (entropy)

Question 3

Why do living systems defy the second law of thermodynamics?

Answer 3

open systems maintain and increase their organization

Question 4

what is the energy in a system available for dong work and is equal to energy in chemical bonds minus unusable energy?

Answer 4

Free energy

Question 5

What reaction release free energy, is spontaneous and slow, and the system loses free energy (downhill)

Answer 5

Exergonic reactions

Question 6

What reaction needs free energy to be added to the system, is uphill, and products have more energy than reactants and is powered by ATP in organisms?

Answer 6

Endergonic reactions

Question 7

What is the energy needed to break chemical bonds and form reaction products?

Answer 7

Activation energy

Question 8

True or False:
ALL reactions need activation energy to proceed

Answer 8

True

Question 9

True or False:
Can increasing temperature provide activation energy?

Answer 9

True

Question 10

What do organisms use that are chemical substances that accelerate reaction rates without being changed by the reaction and without affecting the products?

Answer 10

Catalysts

Question 11

What are biological catalysts that reduce required activation energy for a reaction, does not supply activation energy and lower the activation energy barrier?

Answer 11

Enzyme

Question 12

Most enzyme are?

Answer 12

Proteins

Question 13

What suffix do enzyme names use?

Answer 13

-ase

Question 14

What do some enzymes require to function?

Answer 14

Cofactors

Question 15

What are cofactors?

Answer 15

small, non-protein groups and can be metallic ions or coenzymes

Question 16

True or False:
RNA can have enzymatic activity

Answer 16

True

Question 17

What RNA provides activation energy needed for translation?

Answer 17

Ribosomal RNA (rRNA)

Question 18

True or False:
Small RNA fragments in bacteria can recognize and digest viral DNA

Answer 18

True

Question 19

How does an enzyme function?

Answer 19

associating with its substrate

Question 20

What is formed when a substrate binds with an enzyme?

Answer 20

Enzyme-substrate complex

Question 21

True or False:
enzymes that are involved in energy-providing cellular reactions are CONSTANTLY active and operate in sets

Answer 21

True

Question 22

Enzymes have a a high…

Answer 22

High specifity

Question 23

True or False:
enzyme catalyzed reactions are reversible

Answer 23

True

Question 24

True or False:
Reactions tend to go predominantly in one direction

Answer 24

True

Question 25

What does the net direction depend on?

Answer 25

The energy content of the substances involved

Question 26

Enzymes can be regulated in terms of?

Answer 26

Quantity and activity

Question 27

True or False: Genes related to enzyme synthesis can be switched on or off

Answer 27

True

Question 28

True or False: enzymes may be activated or inhibited by the presence or concentration of certain molecules

Answer 28

True

Question 29

What is the final product of a metabolic pathway that inhibits the first enzyme in said pathway?

Answer 29

Feedback inhibition

Question 30

True or False: Many enzymes have active and inactive forms

Answer 30

True

Question 31

What is the energy currency of all organisms?

Answer 31

Adenosine Triphosphate (ATP)

Question 32

ATP provides free energy to enzymes requiring reactions by serving as?

Answer 32

An intermediate in coupled reactions

Question 33

ATP components: adenine and ribose sugar

Answer 33

Adenosine

Question 34

ATP components: consists of 3 phosphate groups connected by high energy phosphoanhydride bonds

Answer 34

Triphosphate group

Question 35

Is ATP an energy-coupling agent or a fuel?

Answer 35

Energy-coupling agent

Question 36

All cells obtain their energy from?

Answer 36

Oxidation-reduction reactions (redox)

Question 37

What is redox?

Answer 37

transfer of electrons from electron donor (reducing agent) to electron acceptor (oxidizing agent)

Question 38

What happens to the electron donor when it LOSES electrons?

Answer 38

becomes oxidized

Question 39

What happens to the electron acceptor when it GAINS electrons?

Answer 39

becomes reduced

Question 40

What does the flow of electrons through a series of carrier molecules produce?

Answer 40

ATP

Question 41

What is the last molecule to be reduced in the chain that also determines the efficiency of cellular metabolism?

Answer 41

Final electron acceptor

Question 42

What are heterotrophs?

Answer 42

organisms that can't synthesize their own food and must obtain from external sources

Question 43

What heterotroph uses molecular oxygen as its final electron acceptor?

Answer 43

Aerobes

Question 44

What heterotroph use a different molecule as the final electron acceptor?

Answer 44

Anaerobes

Question 45

True or False: aerobic metabolism is more efficient than anaerobic metabolism

Answer 45

true

Question 46

How much more energy is recovered when oxygen is used as the final acceptor (aerobic)

Answer 46

20x

Question 47

What stage of cellular respiration has the food in the intestines broken down into small molecules that can be absorbed into the blood stream but has no useful energy yield?

Answer 47

Stage I - Digestion

Question 48

What stage of cellular respiration occurs in the cytoplasm (glycolysis) and mitochondria (pyruvic acid conversion) and where most of the glucose is converted into 3-carbon units (pyruvic acid) in the cytoplasm, Acetyl-CoA is formed, and a small amount of ATP is produced?

Answer 48

Stage II - Small molecules to Acetyl-CoA

Question 49

What stage of cellular respiration occurs entirely in the mitochondria and the acetyl-CoA is channeled into the krebs cycle, the acetyl group is completely oxidized to CO2, the electrons released from the acetyl groups travel to carriers that pass them along ETC and the accepted electrons are accepted by oxygen at the end of the chain forms H2O?

Answer 49

Stage III - Final oxidation of fuel molecules

Question 50

What is the overall reaction of cellular respiration?

Answer 50

Glucose + 2 ATP + 36 ADP + 36 P + 6 O2 > 6CO2 + 2 ADP + 36 ATP + 6 H2O