Test 2 (Cell Transport, Enzymes And DNA)

Question 1

Explain how the active site of an enzyme causes a high rate of reaction

Answer 1

Lowers activation energy
Induced fit causes active site to change shape
Enzyme substrate complex causes bond to form/break

Question 2

What is the bond between the phosphate and the pentose sugar?

Answer 2

Phosphodiester bond

Question 3

Describe the function of DNA helicase

Answer 3

Breaks the hydrogen bonds

Question 4

Describe the function for DNA polymerase

Answer 4

Joins adjacent nucleotides forming phosphodiester bonds

Question 5

Contrast the structures of ATP and a DNA nucleotide

Answer 5

ATP has ribose and DNA has deoxyribose
ATP has 3 phosphate groups and DNA nucleotides

Question 6

Describe viral replication

Answer 6

Attachment proteins attach to receptors
Viral nucleic acid enters cell
Nucleic acid replicated in cell

Question 7

Explain why the structure of a membrane is describes as fluid-mosaic

Answer 7

Molecules move (fluid)
Both proteins and phospholipids present (mosaic)

Question 8

Describe and explain the appearance of a chromosome

Answer 8

2 chromatids joined together
Connected at centromere

Question 9

What happens in prophase?

Answer 9

The chromosomes condense and become visible

Question 10

What happens in Anaphase?

Answer 10

The chromosomes are pulled to opposite poles of the cell

Question 11

Describe how substances move across cell-surface membrane by facilitated diffusion

Answer 11

Carrier protein involved
Protein specific to substance
Substance moves down conc gradient

Question 12

In what phase of the cell cycle does DNA replication take place?

Answer 12

Synthesis phase (S phase 2)

Question 13

Describe the role of the spindle during mitosis

Answer 13

Attaches the centromeres
Separates the chromatids