Biology Cell Membrane

Question 1

the SEMI-PERMEABLE MEMBRANE surrounding the cytoplasm of a cell.

Answer 1

Cell Membrane

Question 2

The functions of the cell membrane are as follows:

Answer 2

(1) Maintain the shape of the cell;
(2) acts as a
barrier (separates the outside and inside environment of the cell); and
(3) The cell membrane
REGULATES THE TRANSPORT OF THE MATERIALS entering and exiting the cell.

Question 3

THE STRUCTURAL COMPONENTS OF THE CELL MEMBRANE

Question 4

describes the structure of the plasma membrane as a mosaic of components —including
phospholipids, cholesterol, proteins, and carbohydrates—that gives the membrane a fluid character

Answer 4

the Fluid Mosaic Model

Question 5

Fluid Mosaic Model were by

Answer 5

Seymour J. Singer and Garth L. Nicolson (1972).

Question 6

Main fabric of the cell membrane.

Answer 6

PHOSPHOLIPIDS

Question 7

The cell membrane is composed of two layers of
phospholipids wherein

Answer 7

the heads are composed of polar molecules (hydrophilic), whereas the tails are
nonpolar (hydrophobic).

Question 8

Transport substance through cell membrane.

extend from both
side of the phospholipid bilayer. Carrier and channel proteins are examples of this.

Answer 8

INTEGRAL PROTEIN

Question 9

Involved in cell signaling. They are smaller than the integral protein and
usually found either at the top or lowest layer of the phospholipids.

Answer 9

PERIPHERAL PROTEIN

Question 10

involved in cell-to-cell recognition.

Answer 10

CARBOHYDRATES

Question 11

holds the phospholipids together so that they don’t separate too far or compact too
tightly.

Answer 11

CHOLESTEROL

Question 12

THE TRANSPORT MECHANISM OF THE CELL MEMBRANE

Answer 12

PASSIVE AND ACTIVE
TRANSPORT

Question 13

movement of substances across membranes without energy expenditure.

The movement of substance is from high to low concentration.

Answer 13

PASSIVE TRANSPORT

Question 14

There are three types of PASSIVE TRANSPORT

Answer 14

• SIMPLE DIFFUSION,
• FACILITATED DIFFUSION, AND
• OSMOSIS

Question 15

the movement of molecules through a cell membrane without using the channel protein
from an area of high concentration to low concentration

this is suited for small nonpolar molecules (O2, CO2, N2, etc.)

Answer 15

SIMPLE DIFFUSION

Question 16

the movement of molecules through a cell membrane with the help of channel protein
from an area of high concentration to low concentration.

this is suited for big polar molecules (ex. Glucose and amino acids)

Answer 16

FACILITATED DIFFUSION

Question 17

The movement of solvent across a membrane from high to low solvent concentration.

Channel protein is also used in this process.

movement of solvent (water and alcohol)

solvent follows the concentration of solute

Water molecules follow the concentration of solute. They may also require a channel protein
since they cannot pass the phospholipid bilayer because of their polarity.

Answer 17

OSMOSIS

Question 18

(too much solvent outside)

Answer 18

hypertonic

Question 19

(too much solute inside)

Answer 19

hypotonic

Question 20

equal

Answer 20

isotonic

Question 21

movement of across a membrane which requires the expenditure of energy, usually in the
form of adenosine triphosphate (ATP)

The movement of substance is from low to high concentration.

Answer 21

ACTIVE TRANSPORT

Question 22

➢is a type of active transport that moves large molecules, parts of cells, and even whole cells, into a cell.

Answer 22

BULK TRANSPORT

Question 23

➢There are two types of bulk transport:

Answer 23

• ENDOCYTOSIS
• EXOCYTOSIS

Question 24

A process by which cells absorb external material by engulfing it with the cell membrane.

Answer 24

ENDOCYTOSIS

Question 25

A process of removing materials from the cell into the external environment of the cell.

This mechanism is being assisted by the Golgi body (packaging center of the cell).

Answer 25

EXOCYTOSIS