LESSON 8

Question 1

a membrane made of two layers of phospholipids with embedded proteins that separates the insides of the cell from its environment

Answer 1

cell membrane

Question 2

This is a group of organic compounds that are insoluble in water.

Answer 2

lipids

Question 3

Examples include fats, waxes, oils, and hormones.

Answer 3

lipids

Question 4

hydrophilic head

Answer 4

phosphate group

Question 5

hydrophobic tail

Answer 5

fatty acids

Question 6

having both hydrophilic and hydrophobic parts.

Answer 6

amphipathic molecule

Question 7

allows certain substances to pass through but not others.

Answer 7

semi- permeable

Question 8

hese molecules are madeup of building blocks called amino acids joined by peptide bonds.

Answer 8

proteins

Question 9

_______ penetrate the hydrophobic core

Answer 9

Integral proteins

Question 10

Integral proteins that span the membrane are called __________

Answer 10

transmembrane proteins

Question 11

The hydrophobic regions of an integral protein consist of one or more stretches of ____________, often coiled into ___________

Answer 11

nonpolar amino acids; alpha helices

Question 12

___________ - spans across the membrane

Answer 12

polytropic or transmembrane

Question 13

_________ attached to only one side of the membrane

Answer 13

monoprotic

Question 14

are bound to the surface of the membrane

Answer 14

Peripheral proteins

Question 15

Functions of Proteins

Answer 15

receptor
channel
transmembrane transport
adhesion
cell-cell recognition
enzymatic function

Question 16

________ are a special class of proteins that function by binding a specific ligand molecule.

Answer 16

Receptors

Question 17

When a ligand binds to its ______, the ______ can change conformation, transmitting a signal into the cell.

Answer 17

receptor

Question 18

common ligands are the

Answer 18

neutral molecules water (H2O), ammonia (NH3), and carbon monoxide (CO) and the anions cyanide (CN-), chloride (Cl-), and hydroxide (OH-).

Question 19

A __________ is a special arrangement of amino acids which embeds in the cell membrane, providing a hydrophilic passageway for water and small, polar ions.

Answer 19

channel protein

Question 20

Like all transport proteins, each _________ has a size and shape which excludes all but the most specific molecules.

Answer 20

channel protein

Question 21

A ___________ is seen, embedded within the membrane. Ions, the small green hexagons, travel through the channel protein.

Answer 21

generic channel protein

Question 22

A _____________ is a membrane protein involved in the movement of ions, small molecules, and macromolecules, such as another protein, across a biological membrane.

Answer 22

membrane transport protein (or simply transporter)

Question 23

Only ________ proteins can function on both sides of the bilayer or transport molecules across it

Answer 23

transmembrane

Question 24

__________ are transmembrane proteins that bind signal molecules in the extracellular space and generate different intracellular signals on the opposite side of the plasma membrane.

Answer 24

Cell-surface receptors

Question 25

This particular function is useful in the immune system, as it helps the body to recognize foreign cells that may be causing infection, for instance.

Answer 25

cell recognition of proteins

Question 26

this means that they are able to carry out chemical reactions.

Answer 26

enzymatic activity;

Question 27

This can be to induce signal transduction of signals into the cell, such as catalyzing phosphorylation of another protein.

Answer 27

enzymatic activity

Question 28

It is a biomolecule made up of carbon, hydrogen, and oxygen.

Answer 28

carbohydrates

Question 29

Sugar, starches and fiber are some of its examples. mostly found on the external surface

Answer 29

carbohydrates

Question 30

Attached to proteins

Answer 30

glycoproteins

Question 31

attached to lipids

Answer 31

glycolipids

Question 32

Forms distinctive cellular markers

Answer 32

carbohydrate

Question 33

cell-cell recognition Cell pathogen recognition

Answer 33

carbohydrate

Question 34

It is a type of lipid, a waxy substance found in cells.

Answer 34

cholesterol

Question 35

It is essential in the production of other biomolecules like hormones, steroids and vitamin D.

Answer 35

cholesterol

Question 36

regulates the fluidity of the membrane as temperature varies

Answer 36

cholesterol

Question 37

*high temperature → _____ fluidity

Answer 37

decrease

Question 38

low temperature → _____ fluidity

Answer 38

increase

Question 39

fluid mosaic model by

Answer 39

Singer and Nicolson 1972

Question 40

FUNCTIONS OF CELL MEMBRANE

Answer 40

Protection Material Transport Cell Shape Compartmentalization Cell Recognition Cell Function

Question 41

It serves as a barrier that separates the components of the cell from its surrounding environment.

Answer 41

Protection

Question 42

It is a semi-permeable membrane that regulates the transport of materials in and out of the cell.

Answer 42

Material Transport

Question 43

It serves as the attachment point of the cytoskeleton which aids in maintaining the shape and form of a cell.

Answer 43

Cell Shape

Question 44

It separates the organelles from each other and from the cytoplasm providing their own environment and functional individuality

Answer 44

Compartmentalization

Question 45

It enable cells to identify other cells and foreign substances.

Answer 45

Cell Recognition

Question 46

It plays a vital role in the performance of the cell's function i.e. locomotion, absorption,impulse transmission

Answer 46

Cell Function