Molecular and Cellular Bases- Final Exam Obj

Question 1

What are the 5 components that make up a cell?

Answer 1

Water, ions, proteins, lipids, and carbohydrates

Question 2

What are the functions of water in the cell?

Answer 2

It is the principal fluid medium (except for fat cells), water dissolves cellular chemicals.

Chemical reactions can take place among the dissolved chemical, at the surface of suspended particles, and in membranes.

Question 3

What are the functions of ions in the cell?

Answer 3

They provide inorganic chemicals for cellular reactions

They are necessary for operation of some of the cellular control mechanisms

Question 4

What are the functions of proteins in the cell?

Answer 4

All physiological change is mediated by proteins

The 3D shape of proteins determine their function. They can bind to other molecules (lock and key) or change shape and alter binding process

Question 5

What are the most abundant substances in the cell?

Answer 5

Water then proteins

Question 6

What are the major types of proteins?

Answer 6

structural and functional

Question 7

What are the functions of lipids in the cell?

Answer 7

Key components of plasma membrane, nuclear membrane, ER, Golgi apparatus, endosomes, and lysosomes.

They create phospholipid bilayer!! Forms barriers that separate the different cell compartments

Question 8

What cells specialize in lipid storage?

Answer 8

adipocytes

95% of adipocytes are triglycerides

Question 9

What is the body’s main storehouse of energy-giving nutrients?

Answer 9

Adipocytes

Question 10

What are the functions of carbohydrates in the cell?

Answer 10

Play a major role as a source of energy

Can be stored in small amounts in the cell as glycogen, glucose is the readily available form in the ECF

Question 11

Describe cell membrane composition.

Answer 11

The cell membrane is composed almost entirely of lipids and proteins consisting of:
Lipid Bilayer
Instrinic membrane proteins embedded in the lipid bilayer
The outer surface contains carbohydrates in combination with lipids and proteins

Question 12

What are the functions of the lipid bilayer and what is it composed of?

Answer 12

It is impermeable to water-soluble substances and composed of phosolipids, sphingolipids, cholesterol.

Question 13

What are the 2 major types of membrane proteins? Tell me about them.

Answer 13

integral proteins: permanently attached, act as channels, transporters, and receptors; usually transmembrane proteins

peripheral proteins: are attached to one surface of the membrane, often attached to integral proteins, act as enzymes or as controllers of the channels

Question 14

What are the functions of biological membranes?

Answer 14

compartmentalization, selective transport, information processing and transmission, organizing biochemical reactions in space

Question 15

What are the functions of membrane potential?

Answer 15

Allows cell to function as a battery, providing power to operate a variety of molecular devices in the membrane.

Electrically excited cell is used for transmitting signal between different parts of a cell

Question 16

What is passive transport?

Answer 16

Diffusion. Molecules move down their concentration gradient. Does not require cell to use energy.

Question 17

What is active transport?

Answer 17

Molecules move against an energy gradient and use cellular energy to do so.

Question 18

What are cell receptors and where are they located?

Answer 18

A receptor is a protein molecules that receives chemical signals from outside the cell.

Hydrophilic signal molecules are located on the cell surface. Hydrophobic signal molecules are intracellular and located in the cytoplasm or nucleus.

Question 19

What activates a cell receptor?

Answer 19

the binding of ligand

Question 20

List the 3 most common cell surface receptors.

Answer 20

Ligand gated ion channels, G-protein coupled receptors and enzyme coupled receptors