1. Which DNA sequence is recognized first to initiate transcription in eukaryotes?

A. TATA box

B. poly A sequence

C. coding sequence

D. enhancer

2. Strand initiation in DNA replication is accomplished when the enzyme primase lays down a primer. In prokaryotes, of what molecule is that primer composed?

A. DNA

B. RNA

C. protein

D. lipid

Biochemistry

a. What is an "apparent Km"?

b. What is K_I?

c. What is a? (in the context of enzyme inhibition equations!)

d. What is the difference between reversible and irreversible inhibitors? In what category does competitive, uncompetitive and mixed inhibition belong?

e. What is a suicide inhibitor (or suicide inactivator)? Why would this type of inhibition also be called “mechanism-based inactivators”?

Which of the following best describes how ubiquitin terminates Cdk complex activity?

Group of answer choices

Ubiquitin promotes transcription of Cdk complex inhibitors

Ubiquitin chains are added to the cyclin, directing it to the proteasome for degradation

Ubiquitin activates membrane pumps that re-establish Ca²⁺ gradients

Ubiquitin binds to the Cdk active site and inhibits its enzyme activity

An enzyme-catalyzed reaction was carried out in a solution buffered with 0.03 M phosphate, PH 7.2. As a result of the reaction, 0.004mole/liter of acid was formed

a) What is the pH at the end of the reaction.?

b) what would the pH if No buffer were present?

Answers for questions a and b are pH = 6.9 and pH =2.4 respectively. BUT HOW DID THEY GET THOSE pH?

1. If you took an enzyme from your stomach (ph=2) and placed it inside the intestines (ph=8) would it still have catalytic active? Explain
2. How do molecules unable to diffuse across the bilayer get into/out of the cell?
3. What is the structure of the lipid bilayer? How does the structure allow the membrane to interact with the environment?

In humans, most NADPH is produced by the following reaction (not discussed in this course):

Glucose 6-phosphate + H₂O + NADP⁺à 6-phosphogluconate +NADPH +H⁺. This reaction is catalyzed by an enzyme called glucose 6-phosphate dehydrogenase.

Could inhibiting glucose 6-phosphate dehydrogenase be a useful strategy for lowering high cholesterol? Explain, and note any possible complications.

6. Now thinking about digestion, describe the relationship you see regarding why mechanisms exist to control the secretion of the various digestive juices (and, in some instances, their enzymatic composition) as compared to the amount of substrate that is in the digestive tract at a given time.

7. What consequences would the rate at which an enzyme works to convert a substrate to a product have in the digestive system?

Assess the impact human behavior can have on IT changes, indicating how the impact should be managed. Create a strategy to minimize the risk or the negative impact of human intervention.