PCAT Exam Questions

Question 1

Hydrogen bonds in water make water what

Answer 1

Polar solvent
Surface for small particles and living organisms to move across
High boiling point
high specific heat

Question 2

The breakdown of a disaccharide releases energy which is stored as ATP. This is an example of what type of reaction?

Answer 2

Exothermic

Question 3

Of the following metabolic cpds, which consists of only C,H, and oxygen?
Phosphlipids
Glycogen
Peptides
RNA
Vitamins

Answer 3

Glycogen

Question 4

When an animal takes in more energy that it uses over an extended time, the extra chemical energy is stored as

Answer 4

Fat

Question 5

Name the molecule that is thought to have acted as the first enzyme in early life on earth

Answer 5

RNA

Question 6

Name the organelle formed when the plasma membrabne surrounds a particle outside the cell

Answer 6

Endocytic vessicle

Question 7

Name the plant organelle that contains a pigment that givs leaves their color

Answer 7

Chloroplast

Question 8

All but which of the following processes are ways of moving solutes across a plasma membrane?
Osmosis
Passive Transport
Active transport
Facilitated diffusion
Endocytosis

Answer 8

Osmosis

Question 9

Prokaryotic and Eukaryotic cells are similar in having which of the following
Membrane bound organelles
Protein-studded DNA
Presence of a nucleus
Intergral membrane proteins in the plasma membrane
Flagella composed of microtublues

Answer 9

Intergral membrane proteins in the plasma

Question 10

Which of the following cell types has a peptidoglycan cell wall
Algae
Bacteria
Fungi
Land plants
Protists

Answer 10

Bacteria

Question 11

Enzymes catalyze biochemical reactions by

Answer 11

Lowering the activation energy of the reaction

Question 12

What are cofactors usually?

Answer 12

Metal such as zinc, Iron

Question 13

What are coenzyme usually

Answer 13

Vitamins

Question 14

Cyanide is a poison that binds to the active suite of the enzyme cytochrome c and prevents its activity. Cyanide is acting as a(n)?

Answer 14

Inhibitor

Question 15

What are the characteristics of an endergonic reaction?

Answer 15

Non spontaneous. Requires heat. Products have more energy than starting materials

Question 16

What are the characteristics of an exergonic reaction?

Answer 16

Spontaneous. No heat required. Products have less energy than starting materials

Question 17

Name characteristics of enzymes

Answer 17

Change shape when they bind their substrates
Can catalyze reactions in both forward and reverse directions
Sensitive to temp and pH changes
Specific
They may have more than one binding site

Question 18

In a strenuously exercising muscle, NADH begins to accumulate in high conc. Name the metabolic process that will be activated to reduce the concentration of NADH

Answer 18

Lactic acid fermentation

Question 19

Which of the following statements regarding chemiosmosis in mitochondria is incorrect?
1 ATP synthase is powered by protons flowing through the membrane channels
2. Energy from ATP is used to transport protons to the intermembrane space
3. Energy from the electron transport chain is used to transport protons to the intermembrane space
4. An electrical and a pH gradient both exist across the inner membrane
5. The waste product of chemiosmosis is water

Answer 19

2. Energy from ATP is used to transport protons to the intermembrane space

Question 20

In photosynthesis, high-energy electrons move through electron transport chains to produce ATP and Nto create high energy electrons?ADPH. What provides the energy

Answer 20

Light

Question 21

Which of the following kinds of plants is more likely to perform CAM photosynthesis?
Mosses, Grasses, Deciduous trees, Cacti, Legumes

Answer 21

Cacti