560B Biochemistry

Question 1

The type of reaction that occurs when energy is (absorbed) from our surroundings in the form of heat.
A. Endothermic
B. Exothermic

Answer 1

Endothermic

Question 2

Type of reaction where energy is (released) from the system and into surroundings.

Answer 2

Exothermic

Question 3

When two similar or dissimilar types of chemical species react together with a common intermediate with the help of a metal catalyst to get a new product.

Answer 3

Coupling Reaction

Question 4

A nucleotide made from an adenosine molecule attached to three other phosphate groups via phosphoanhydride bonds. It contains has three main parts in its complete composition: adenine, sugar, and triphosphate and is the main currency for energy.

Answer 4

ATP

Question 5

Glycolysis takes place in the cytoplasm. True/False

Answer 5

True

Question 6

Kreb Cycle occurs in the mitochondria. True/False

Answer 6

True

Question 7

The electron transport chain occurs in the
A. Cytoplasm
B. Mitochondria

Answer 7

B Mitochondria

Question 8

Which pathway generates the most ATP?

Answer 8

Oxidative Phosphorylation (Electron Transport Chain/Chemiosmosis)

Question 9

Where is glucose 6 phosphatase found?

Answer 9

ER (endoplasmic reticulum)

Question 10

3 key enzymes of glycolysis

Answer 10

Glucokinase/Hexokinase
Phosphofructokinase (PFK)
Pyruvate Kinase

Question 11

4 Key enzymes of gluconeogenesis

Answer 11

Pyruvate carboxylase
Phosphoenolpyruvate Carboxykinase (PEPCK)
Fructose 1,6 Bisphosphatase
Glucose 6 Phosphatase

Question 12

How many ATP are made in the Kreb Cycle?

Answer 12

2 ATP

Question 13

The electron transport chain occurs in the:

Answer 13

mitochondria

Question 14

How does glucose 6 phosphatase regulate blood sugar levels?

Answer 14

D -glucose 6-phosphate + H 2 O = D -glucose + phosphate Glucose is exported from the cell via glucose transporter membrane proteins. This catalysis completes the final step in gluconeogenesis and therefore plays a key role in the homeostatic regulation of blood glucose levels

Question 15

FAD enters ETC (electron transport chain) at which complex?

Answer 15

complex 2

Question 16

NADH enters ETC at what complex?

Answer 16

complex 1

Question 17

Coenzyme Q10 is connected to which complexes in the ETC?

Answer 17

1, 2, 3

Question 18

what is Oxidative Phosphorylation ?

Answer 18

The metabolic pathway in which cells use enzymes to oxidize nutrients, thereby releasing chemical energy in order to produce adenosine triphosphate (ATP). In eukaryotes, this takes place inside mitochondria.

Question 19

How many Protein complexes in the ETC?

Answer 19

There are four protein complexes that are part of the electron transport chain that functions to pass electrons down the chain. A fifth protein complex serves to transport hydrogen ions back into the matrix. These complexes are embedded within the inner mitochondrial membrane.

Question 20

What are the 2 end products of oxidative phosphorylation?

Answer 20

ATP & Water

Question 21

How many ATP are made during oxidative phosphorylation?

Answer 21

32-34 ATP

Question 22

Explain the generation of free radicals

Answer 22

When cells use oxygen to generate energy, free radicals are created as a consequence of ATP (adenosine triphosphate) production by the mitochondria. These by-products are generally reactive oxygen species (ROS) as well as reactive nitrogen species (RNS) that result from the cellular redox process.

Question 23

Describe the role of oxygen in oxidative phosphorylation

Answer 23

Oxidative phosphorylation uses these molecules and O 2 to produce ATP, which is used throughout the cell whenever energy is needed. During oxidative phosphorylation, electrons are transferred from the electron donors to a series of electron acceptors in a series of redox reactions ending in oxygen, whose reaction releases half of the total energy.

Question 24

Explain Fructose and Galactose pathways

Answer 24

Even though glucose, galactose and fructose are metabo- lized through different pathways (Fig. 2), they all serve as substrates for glycogen synthesis and all regulate the activity of liver glycogen synthase. That is, not only are these monosaccharides substrates for glycogen synthesis, but they also regulate their own disposition in the liver, a very elegant system. Because of the regulatory activity of these monosaccharides, we developed an interest in the regulation of the glucose, fructose and galactose concentrations in the circulation, and thus in the liver cell.

Question 25

Describe the PPP (pentose phosphate pathway)

Answer 25

PPP is a metabolic pathway parallel to glycolysis.[1] It generates NADPH and pentoses (5-carbon sugars) as well as ribose 5-phosphate, a precursor for the synthesis of nucleotides.[2] While the pentose phosphate pathway does involve oxidation of glucose, its primary role is anabolic rather than catabolic. The pathway is especially important in red blood cells (erythrocytes).

Question 26

What is glucagon?

Answer 26

a natural substance that raises blood sugar by causing the body to release sugar stored in the liver.

Question 27

Liver's role in energy homeostasis?

Answer 27

Glucose homeostasis is tightly regulated to meet the energy requirements of the vital organs and maintain an individual’s health. The liver has a major role in the control of glucose homeostasis by controlling various pathways of glucose metabolism, including glycogenesis, glycogenolysis, glycolysis and gluconeogenesis.

Question 28

What are ketone bodies?

Answer 28

Ketone bodies are produced from fatty acids, released by adipose tissue, and from ketogenic amino acids. (fasted state)

Question 29

The catabolic process by which fatty acid molecules are broken down in the cytosol in prokaryotes and in the mitochondria in eukaryotes to generate acetyl-CoA

Answer 29

Beta oxidation

Question 30

Where does beta oxidation occur?

Answer 30

mitochondria

Question 31

Describe triaclycerol synthesis and hydrolysis into free glycerol and fatty acids

Answer 31

Hydrolysis of Triacylglyerols Energy production from triacylglycerols starts with their hydrolysis into free fatty acids and glycerol. In adipose (fat‐storing) tissue, this hydrolysis is carried out by a cellular lipase, which catalyzes the hydrolysis reaction to release the free fatty acids and glycerol.

Question 32

The creation of fatty acids from acetyl-CoA and NADPH through the action of enzymes is called:

Answer 32

fatty acid synthases.

Question 33

Differentiate between odd and even chain fatty acid breakdown

Answer 33

Fatty acids with an odd number of carbons are a minor species and are oxidized in the same way as fatty acids with an even number of carbons. The difference is that when the odd-numbered fatty acid is oxidized, it produces propionyl CoA and acetyl CoA in the final round of degradation rather than two molecules of acetyl CoA.

Question 34

A chemical reaction that transfers an amino group to a ketoacid to form new amino acids. This pathway is responsible for the deamination of most amino acids. This is one of the major degradation pathways which convert essential amino acids to non-essential amino acids (amino acids that can be synthesized de novo by the organism).

Answer 34

Transamination

Question 35

Galactose is not as effective as glucose, so must shift to glucose 1 phosphate before entering glycolysis. True or false.

Answer 35

True (and the process costs 1 ATP)

Question 36

What transporter does fructose use for absorption?

Answer 36

GLUT 5 transporter

Question 37

Fed state pathways:

Answer 37

glycolysis, kreb cycle or glucose stored as glycogen.

Question 38

Fasting state pathways:

Answer 38

glucagon levels rise as plasma insulin declines. liberation of fatty acids/TG