2. At what point do the carbon atoms of each of the following amino acids enter metabolic pathways for the production of energy? State citric acid cycle, etc.

a. valine b. proline c. glycine

Which of the following changes leads to an increase in entropy of the system?

The evaporation of water from a puddle

The freezing of water into an ice cube

The formation of starch from glucose molecules

The digestion of protein into amino acids

None of these

What is the simplest evolutionary explanation for:

1. Nucleotide synthesis uses several amino acids
2. Deoxyribose is made from ribose

Hint: Determine which one came first. Provide detailed answer for full credit!

Laboratory: Enzyme Activity

In this laboratory you will examine factors that affect enzyme activity.

Catalase is an enzyme found in the liver that breaks down hydrogen peroxide into water and oxygen gas. It catalyzes the following reaction:

H2O2 H2O + O2

You will examine two factors that affect its activity.

Part A: The Effect of Temperature on Enzyme Activity

Graph the volume of oxygen produced against the temperature of the solution.

How is the oxygen production in 30 seconds related to the rate of the reaction?

At what temperature is the rate of reaction the highest? Lowest? Explain.

Why might the enzyme activity decrease at very high temperatures?

Why might a high fever be dangerous to humans?

What is the optimal temperature for enzymes in the human body?

Part B: The Effect of pH on Enzyme Activity

Graph the volume of oxygen produced against the pH of the solution.

At what pH is the rate of reaction the highest? Lowest? Explain.

Why does changing the pH affect the enzyme activity?

Research the enzyme catalase. What is its function in the human body?

What is the optimal pH for the following enzymes found in the human body? Explain. (catalase, lipase (in your stomach), pepsin, salivary amylase)

I would highly appreciate if it was in a text form not handwritten.

Thank you very much.

6. Aminoacyl-tRNA synthetases catalyses _____ 1. DNA replication 2. transcriptional termination 3. the attachment of amino acids to the tRNA molecules. 4. the binding of mRNA to the 30S subunit. 5. the removal of the polypeptide from tRNA in the P site and transferal to the amino acid at the A site 7. If the strand “5'-TACGCCT-3'” is a template strand, what would the mRNA strand look like? 1. 5'-AGGCGUA-3' 2. 3'-AUGCGGA-5' 3. 3'-ATGCGGA-5' 4. 5'-AGGCGTA-3' 5. 5'-UGGCGTU-3' 8. A repressor is a______. 1. regulatory protein that increases the rate of transcription 2. regulatory protein that binds to DNA and inhibits transcription 3. form of positive control. 4. small effector molecule that causes transcription to increase 5. enzyme that converts lactose to allolactose 9. Complete the following statement: When there is lactose in the medium and no glucose, the cAMP concentration is _____. 1. low 2. medium 3. high 4. inhibited by negative feedback 5. negatively regulated 10. Antisense RNA________ 1. carries a codon during translation 2. is a strand of RNA, complementary to a specific mRNA strand. 3. cleaves RNA into fragments 4. functions in the translation of proteins 5. are sequences that increase gene expression

The protein synthesis can be divided in three phases: initiation, elongation and termination.

a. Describe the initiation phase as it takes place in bacteria.

b. The initiation phase in pro- and eukaryotes begin differently, when it concern the recognition of mRNA, describe these differences.

c. tRNA transport amino acids to the ribosome. Which part of the tRNA molecule form a covalent link to the amino acid? And what is the name for the general class of enzymes that catalyse the formation of a covalent bond between tRNA and aminoacids?

d. Describe the mechanism which ensure that only the amino acid threonine is attached to threonyl-tRNA.

Which of the following provides nutrients, including water, to microorganisms so they can grow and produce?

Group of answer choices

Growth media

Salt compounds only

Yeast extract is the main component

Only amino acids

Which phenomenon related to protein structure involves nonpolar side chains of multiple amino acids?

A. Hydrophobic interactions

B. Hydrogen bonds

C. Covalent bonds

D. Disulfide bonds

E. Peptide bonds

What is the net charge of the dipeptide Glu-Ala at pH=4.1, given the following data for the individual amino acids:

Glu: pKa1= 2.1; pKa2= 9.5; pKaR= 4.1
Ala: pKa1 = 2.3; pKa2 = 9.9

Which of the following terms would be used to describe a food that is good at providing all of the essential amino acids?

Question 19 options:

Why are nonessential amino acids said to be nonessential?

Question 17 options:

Which of the following lipids improve blood cholesterol levels?

Question 7 options:

True or false: All lipids are fats.