Bio

Question 1

The tendency of the body to oppose flow is known as ________.

Answer 1

The tendency of the body to oppose flow is known as resistance.

Question 2

Stenosis, or narrowing, of the afferent arteriole would cause a(n) _______ in resistance because of the reduced diameter of the afferent arteriole

Answer 2

Stenosis, or narrowing, of the afferent arteriole would cause an increase in resistance because of the reduced diameter of the afferent arteriole

Question 3

The outside of a cell has a net ____ charge

Answer 3

The outside of a cell has a net + charge, more Na+ and less K+ (3 Na+ out, 2 K+ in)

Question 4

The resting membrane potential of neurons is approximately ____ mV, which is close to K+ resting potential.

Answer 4

The resting membrane potential of neurons is approximately −70 mV, which is close to K+ resting potential.

Question 5

What is the initial rise in the action potential due to?

Answer 5

Na+

Question 6

What cells are myelin sheaths produced by?

Answer 6

Glial cells

Question 7

What kind of channels are found at the nodes of Ranvier in myelinated axons?

Answer 7

Voltage-gated ion channels are clustered at the nodes of Ranvier; in unmyelinated axons, they are evenly distributed

Question 8

How do electrical synapses transfer information?

Answer 8

Electrical synapses transfer information from one cell to another via passive ionic current flow through gap junctions almost instantaneously since the cells are continous

Question 9

Explain the steps in a chemical synapse

Answer 9

Question 10

Is the cytosol side hydrophobic or hydrophillic?

Answer 10

Hydrophillic

Question 11

What amino acid are serine and threonine very similar to?

Answer 11

Alanine

Question 12

Which amino acids have amide groups?

Answer 12

Asparagine and glutamine

Question 13

How does SDS page separate proteins?

Answer 13

By size

(anode is the + side)

Question 14

Which mRNA functions in RNA interference by binding target complementary seq on mRNA molecule to silence gene expression?

Answer 14

miRNA

Question 15

Which RNA associates with specific proteins to form snRNPs, the building blocks of spliceosomes?

Answer 15

snRNA

Question 16

Which RNA functions in RNA interference by binding complementary mRNA and signals for its degredation?

Answer 16

siRNA

Question 17

Which way does Km and Vmax increase in a Lineweaver Burk plot?

Answer 17

Question 18

Fatty acid synthesis is an anabolic process that builds lipids in the ____. Anabolic processes generally require precursor molecules: ATP, NADPH, and acetyl-CoA, respectively.

In this process NADPH is oxidized to NADP+

Answer 18

Fatty acid synthesis is an anabolic process that builds lipids in the cytosol. Anabolic processes generally require precursor molecules: ATP, NADPH, and acetyl-CoA, respectively.

In this process NADPH is oxidized to NADP+

Question 19

β-oxidation is the breakdown of fatty acid chains into _____ through a series of oxidation reactions in the mitochondrial matrix that produce ATP; long-chain fatty acids obtained from lipid stores must undergo a set of reactions to enter the mitochondrial matrix.

Answer 19

β-oxidation is the breakdown of fatty acid chains into acetyl-CoA through a series of oxidation reactions in the mitochondrial matrix that produce ATP; long-chain fatty acids obtained from lipid stores must undergo a set of reactions to enter the mitochondrial matrix.

Question 20

During fatty acid synthesis, acetyl-CoA in the mitochondria is converted into ____ and then transported into the cytoplasm, where it is reconverted into acetyl-CoA and oxaloacetate.

Answer 20

During fatty acid synthesis, acetyl-CoA in the mitochondria is converted into citrate and then transported into the cytoplasm, where it is reconverted into acetyl-CoA and oxaloacetate.

Question 21

During β-oxidation, long-chain fatty acids are activated with _____ and shuttled by enzymes from the cytoplasm to the mitochondrial matrix. The rate-limiting step of fatty acid oxidation is the conversion of fatty acyl-CoA molecules into ______ by carnitine acyltransferase I.

Answer 21

During β-oxidation, long-chain fatty acids are activated with coenzyme A and shuttled by enzymes from the cytoplasm to the mitochondrial matrix. The rate-limiting step of fatty acid oxidation is the conversion of fatty acyl-CoA molecules into fatty acylcarnitine by carnitine acyltransferase I.

Question 22

Insulin _____ lipid synthesis by activating the major enzymes involved in fatty acid production: Pyruvate dehydrogenase complex, acetyl-CoA carboxylase, and fatty acid synthase.

Answer 22

Insulin stimulates lipid synthesis by activating the major enzymes involved in fatty acid production: Pyruvate dehydrogenase complex, acetyl-CoA carboxylase, and fatty acid synthase.

Question 23

_____ amino acids are converted to pyruvate or citric acid cycle intermediates, which can be converted to glucose. _____ amino acids are converted directly to acetyl-CoA, which can enter the citric acid cycle or be used to form ketone bodies.

Answer 23

Glucogenic amino acids are converted to pyruvate or citric acid cycle intermediates, which can be converted to glucose. Ketogenic amino acids are converted directly to acetyl-CoA, which can enter the citric acid cycle or be used to form ketone bodies.

Question 24

What are the functions of the spleen?

Answer 24

Filters damaged RBCs, reservoir for blood, immune response (B cell activation, houses macrophages)

Question 25

Does Gel 1 or Gel 2 represent non-reducing SDS-page?

Answer 25

Gel 1 is non-reducing

Question 26

\_\_\_\_\_\_ is a molecular technique used to determine the nucleotide order of DNA molecules.

Answer 26

**DNA sequencing** is a molecular technique used to determine the nucleotide order of DNA molecules.

Question 27

\_\_\_\_\_\_ is an RNA assay used to assess gene *expression* in different tissues.

Answer 27

**Northern blotting** is an RNA assay used to assess gene *expression* in different tissues.

Question 28

Does vasocontriction or vasodilation increase blood pressure?

Answer 28

Vasoconstriction

Question 29

Which bond, cis or trans, increases membrane fluidity?

Answer 29

Cis - this configuration is particularly important in cell membranes as it introduces a bend or "kink" in the fatty acid that prevents phospholipids from stacking together and solidifying.

Question 30

Each phospholipid has a unique \_\_\_\_, \_\_\_\_, and _____ due to distinct features in the backbone, polar head groups, and fatty acid chains.

Answer 30

Each phospholipid has a unique **mass, charge, and solubility** due to distinct features in the backbone, polar head groups, and fatty acid chains.

Question 31

What are examples of hydrolyzable lipids and non-hydrolyzable lipids?

Answer 31

(Note: all lipids can be emulsified)

Question 32

What is Kcat = to?

Answer 32

Kcat = vmax / E total

Question 33

Reactions in which n \> 1 display _____ cooperativity whereas reactions where n = 1 or n \< 1 exhibit ____ cooperativity or _____ cooperativity, respectively.

Answer 33

Reactions in which n \> 1 display **positive cooperativity** whereas reactions where n = 1 or n \< 1 exhibit **no cooperativity** or **negative cooperativity**, respectively.

Question 34

T/F: cell membranes are composed largely of phospholipids, which act as a fluid that allows other membrane components such as transmembrane proteins, glycoproteins, cholesterol, and glycolipids to migrate through this environment laterally.

Answer 34

T: cell membranes are composed largely of phospholipids, which act as a fluid that allows other membrane components such as transmembrane proteins, glycoproteins, cholesterol, and glycolipids to migrate through this environment laterally.

Question 35

The secretory pathway involves the processing of proteins as they go through the _____ and the \_\_\_\_. After processing in the Golgi, proteins destined for the cell membrane are packed into secretory vesicles, which fuse with the plasma membrane.

Answer 35

The secretory pathway involves the processing of proteins as they go through the **endoplasmic reticulum and the Golgi apparatus**. After processing in the Golgi, proteins destined for the cell membrane are packed into secretory vesicles, which fuse with the plasma membrane.

Question 36

\_\_\_\_\_ can participate in retrograde trafficking, which refers to the reversal of a pathway in the context of cellular trafficking. In this case, retrograde trafficking leads to endosomes producing vesicles that fuse with the Golgi apparatus.

Answer 36

**Endosomes** can participate in retrograde trafficking, which refers to the reversal of a pathway in the context of cellular trafficking. In this case, retrograde trafficking leads to endosomes producing vesicles that fuse with the Golgi apparatus.

Question 37

Which glycolysis intermediate could serve as the sole starting material of the synthesis of R5P in muscle tissue? a. Fructose 6 phosphate b. Glyceraldehyde 3 phosphate c. fructose 1, 6 bisphosphate d. dihydroxyacetone phoephate

Answer 37

a. Fructose 6 phosphate

Question 38

The free energy available in each ATP molecule is ___ kJ/mol

Answer 38

The free energy available in each ATP molecule is **−30 kJ/mol**

Question 39

\_\_\_\_\_ is the enzyme in the pentose phosphate pathway that catalyzes the conversion of 6-phosphogluconate to R5P.

Answer 39

**6-Phosphogluconate dehydrogenase (6PGD)** is the enzyme in the pentose phosphate pathway that catalyzes the conversion of 6-phosphogluconate to R5P.

Question 40

Are D-mannose and D-glucose: a. epimers b. enantiomers c. constiutional isomers d. anomers

Answer 40

a. epimers; only differ at 1 stereocenter

Question 41

\_\_\_\_ are stereoisomers that differ at every stereocenter, not just one.

Answer 41

**Enantiomers** are stereoisomers that differ at every stereocenter, not just one.

Question 42

All monosaccharides are reducing sugars. What are two examples?

Answer 42

Galactose and ribose

Question 43

Lactose is a _____ sugar

Answer 43

Lactose is a _____ sugar; it has a free anomeric carbon (NOTE: SUCROSE IS A NON-REDUCING SUGAR)

Question 44

Histidine (H) can contribute only a ____ charge to a peptide, so it can only increase pI.

Answer 44

Histidine (H) can contribute only a **positive** charge to a peptide, so it can only increase pI.

Question 45

Ionizable side chains that contain oxygen or sulfur (\_\_, \_\_, \_\_, \_\_) are negatively charged when deprotonated and tend to decrease pI.

Answer 45

Ionizable side chains that contain oxygen or sulfur (**Y, C, E, and D**) are negatively charged when deprotonated and tend to decrease pI

Question 46

A drop in BP causes the juxtaglomerular cells in the kidneys to release \_\_\_\_, an enzyme that cleaves the plasma protein angiotensinogen to form angiotensin I.

Answer 46

A drop in BP causes the juxtaglomerular cells in the kidneys to release **renin**, an enzyme that cleaves the plasma protein angiotensinogen to form angiotensin I.

Question 47

Angiotensin-converting enzyme (ACE) cleaves ____ to form \_\_\_\_\_, which ultimately raises BP by inducing both the release of aldosterone from the adrenal cortex and the constriction of arterioles.

Answer 47

Angiotensin-converting enzyme (ACE) cleaves **angiotensin I to form angiotensin II,** which ultimately raises BP by inducing both the release of aldosterone from the adrenal cortex and the constriction of arterioles.

Question 48

Long-chain fatty acids are not recognized by any transport proteins; they must be modified or "activated" to enter the matrix. Fatty acid activation and transport requires which of the following: a. ATP b. OAA c. carnitine d. coenzyme A

Answer 48

a. ATP c. carnitine d. coenzyme A In the cytosol, acyl-CoA synthetase catalyzes the reaction with coenzyme A to form acyl-CoA and requires ATP hydrolysis to proceed... Acyl-CoA molecules then migrate to the intermembrane space and react with carnitine to form acylcarnitine. Acylcarnitine translocase recognizes acylcarnitine and carries it into the mitochondrial matrix... Acylcarnitine is then converted back to acyl-CoA and carnitine. Acyl-CoA is digested by β-oxidation, and carnitine transported out of the matrix where it can pick up and carry a new fatty acid into the mitochondrial matrix.