Ch1

Question 1

What is the first principle of cell theory?

Answer 1

All organisms are made up of cells.

Question 2

What is the fundamental unit of life?

Answer 2

The cell is the fundamental unit of life.

Question 3

Where do all cells arise from?

Answer 3

All cells arise from pre-existing cells.

Question 4

What is a nucleoid?

Answer 4

The nucleoid is found in prokaryotic organisms and contains concentrated genetic material.

Question 5

What are organelles?

Answer 5

Organelles divide the cell content into smaller areas specialized for different functions.

Question 6

What defines all cells?

Answer 6

All cells are defined by the cell membrane.

Question 7

What is the major component of the cell membrane?

Answer 7

Phospholipids are the major component of the cell membrane.

Question 8

What does it mean for a molecule to be amphipathic?

Answer 8

Amphipathic molecules have both hydrophobic and hydrophilic regions.

Question 9

What is the hydrophilic part of a phospholipid?

Answer 9

The phosphate head group is hydrophilic.

Question 10

What are the characteristics of fatty acid tails?

Answer 10

Fatty acid tails are hydrophobic and non-polar.

Question 11

What is a micelle?

Answer 11

A micelle is a shape formed by the phosphate head groups.

Question 12

What are liposomes?

Answer 12

Liposomes are spherical bilayer structures formed by phospholipids in water at pH 7.

Question 13

Why are bilayers effective cell membranes?

Answer 13

Bilayers are effective cell membranes because they form closed structures that prevent exposure of hydrophobic chains to water.

This organization explains why membranes are self-healing.

Question 14

What does membrane fluidity refer to?

Answer 14

Membrane fluidity refers to the ability of membrane lipids to move within the plane of the membrane.

Question 15

What factors affect membrane fluidity?

Answer 15

The length of carbon to carbon double bonds and the number of double bonds in fatty acid tails affect membrane fluidity.

Question 16

What is cholesterol’s role in cell membranes?

Answer 16

Cholesterol is a major component of animal cell membranes and is amphipathic.

Question 17

What are transporters in cell membranes?

Answer 17

Transporters are membrane proteins that move ions or molecules across the membrane.

Question 18

What is the function of receptors in cell membranes?

Answer 18

Receptors allow the cell to receive signals from the environment.

Question 19

What role do enzymes play in cell membranes?

Answer 19

Enzymes catalyze chemical reactions.

Question 20

What is the function of anchors in cell membranes?

Answer 20

Anchors help maintain the shape and structure of the cell by attaching to proteins.

Question 21

What are integral membrane proteins?

Answer 21

Integral membrane proteins are permanently associated with cell membranes and cannot be separated without destroying the membrane.

Question 22

What are peripheral membrane proteins?

Answer 22

Peripheral membrane proteins are temporarily associated with the lipid bilayer and can be easily separated.

Question 23

What are transmembrane proteins?

Answer 23

Transmembrane proteins span the entire lipid bilayer.

Question 24

What is the fluid mosaic model?

Answer 24

The fluid mosaic model describes the lipid layer as a structure where molecules move laterally and is a mixture of different types of molecules.