1-

The changing or activation of a tRNA molecule includes:

Group of answer choices

the covalent attachment of an amino acid to the 5' terminal adenosine of the tRNA.

the covalent attachment of an amino acid to the 3' terminal cytosine of the tRNA.

the covalent attachment of the carboxyl group of an amino acid to the tRNA.

the covalent attachment of the amino group of an amino acid to the tRNA.

2-

A difference between a Class I and a Class II tRNA synthetase is (select all that apply):

Group of answer choices

the Class I synthetase requires ATP as a cofactor and the Class II does not.

the Class I synthetase reaction requires a transesterification reaction not necessary in the Class II reaction.

the Class II synthetases are typically monomeric, whereas the Class I enzymes frequently function as multimeric protein complexes.

the Class I synthetase uses the 2' OH of the 3' end of the tRNA as a nucleophile and the Class II uses the 3' OH.

3-

What result allowed Dintzis to conclude that proteins are synthesized from the N terminus to C terminus?

Group of answer choices

All peptides produced from the experiment had similar levels of labeled H and C.

The more newly synthesized peptides had greater levels of radiolabeled C.

Reticulocytes only produce a single protein.

The more newly synthesized peptides had greater levels of radiolabeled H.

1-Common commercial acids and bases are aqueous solutions with the following properties: HCl, density 1.19 g/cm³ and 34% solute by mass. Calculate the molality.

2-Common commercial acids and bases are aqueous solutions with the following properties: HCl, density 1.19 g/cm³ and 35% solute by mass. Calculate the mole fraction.

a. (3 pts) All Brønsted-Lowry acids contain the hydrogen ion, H+ . True False

b. (3 pts) You can use any acid/conjugate base pair in making a buffer. True False

c. (3 pts) Concentration does not matter for acids/conjugate bases in buffers. True False

1. You were trying to produce a hydrophilic protein from E coli, but the protein you produced is inactive (misfolded) due to a disulfide bond formed between two cysteine residues that are not found in the native form. Your professor suggests you to co-express this protein with a folding assistant enzyme to improve its activity.

(a) Which enzyme is it? (0.4 pt)

(b) What are the functions of this enzyme? Please describe two aspects and indicate which sub-form execute which aspect of the function. (0.6 pt)

(c) What structural features allow them to work on many different clients? (0.5 pt)

please answer 1-6 :)

1. Choose the CORRECT enzyme–substrate pair from the pentose phosphate pathway.

a. transaldolase – xylulose 5-phosphate

b. glucose 6-phosphate dehydrogenase – 6-phosphoglucono-δ-lactone

c. 6-phosphogluconate dehydrogenase – 6-phosphoglucono-δ-lactone

d. transketolase – xylulose 5-phosphate

e. lactonase – ribulose 5-phosphate

2. Choose the enzymes that catalyze reactions with concomitant formation of NADPH.

a. glucose 6-phosphate dehydrogenase and lactonase

b. transketolase and transaldolase

c. phosphofructokinase and 6-phosphogluconate dehydrogenase

d. glucose 6-phosphate dehydrogenase and 6-phosphogluconate dehydrogenase

e. phosphopentose epimerase and glucose 6-phosphate dehydrogenase

3. Glucose 6-phosphate dehydrogenase is highly specific for:

a. NADH.

b. NADP+.

c. ADP.

d. NAD+.

e. NADPH.

4. In what tissues is the pentose phosphate pathway active? Select all that apply.

a. pancreas

b. liver

c. red blood cells

d. mammary gland

e. muscle

5. When both NADPH and ATP are required, the intermediates from the pentose phosphate pathway:

enter glycolysis.

restore glucose 6-phosphate by entering the oxidative phase of the pentose phosphate pathway.

enter gluconeogenesis.

restore glucose 6-phosphate by entering the nonoxidative phase of the pentose phosphate pathway.

enter the citric acid cycle.

6. What are the concomitant products of the conversion of glucose 6-phosphate to pyruvate in mode 4 of the pentose phosphate pathway? Select all that apply.

NADPH

CO2

ADP

ATP

NADH

Which of the following statements about the triacylglycerols stored in adipose tissue is correct?

a. they are hydrolyzed to form directly fatty acids and dihydroxyacetone

b. they are hydrolyzed by a lipase that is activated by acetylation

c. they release fatty acids that can be oxidized to pyruvate to provide energy to the cell

d. they can yield a precursor of glucose

Please Describe AND diagram when and how six carbons in glucose are all transferred and released, and in what form (molecule), from glycolysis through the Krebs (TCA) cycle. What else happens each time carbons are released?

Describe in words how fatty acids are released in the body AND how fatty acids arrive at the appropriate cellular location for use (no structures). Beginning from this point, provide the details in words (names of structures, enzymes, cofactors, etc.) for one round of fatty acid degradation.  Include the tissue and cellular locations for each part of the process of harvesting fatty acids for energy. What pathway does the primary product enter next? Provide details in words (names of structures, enzymes, cofactors, etc.) for the reaction steps where carbon leaves the pathway. You don't have to go over the entire pathway – only the steps where carbon is lost.

1. What does the term omega mean with respect to fatty acids? Describe the roles of omega fatty acids in disease prevention.

2. What are the differences between saturated, unsaturated, monounsaturated, and polyunsaturated fatty acids?

3. Describe the structure of a triglyceride.

4. Trace the steps in fat digestion, absorption, and transport. Describe the role cholesterol has in the body.

5. What are the three forms of vitamin A and their function? What is the role of vitamin A in vision, protein synthesis, and cell differentiation?

6. What are the roles of vitamin D in the body?

7. What are the roles of vitamin E in the body?

8. What is an antioxidant and its role in disease and cancer? Which foods are rich in these?