wayground logo

Free Printable Worksheets

NEW

Font size

S
M
L
XL
Worksheets

lecture 1

Total questions: 37

Worksheet time: 19mins

Name
Class
Date
1.

The basic structural unit of the cell membrane is the:

a)

Phospholipid monolayer

b)

Phospholipid bilayer

c)

Protein sheet

d)

Polysaccharide coat

2.

Biological membranes are mainly composed of:

a)

Lipids and proteins

b)

Carbohydrates and nucleic acids

c)

DNA and RNA

d)

Proteins and glycogen

3.

Phospholipids are described as amphipathic because:

a)

They are entirely hydrophobic

b)

They contain both hydrophilic and hydrophobic regions

c)

They are water-soluble

d)

They form hydrogen bonds with proteins only

4.

The hydrophilic head of a phospholipid is:

a)

Non-polar

b)

Polar

c)

Hydrophobic

d)

Lipid-soluble

5.

Which of the following is NOT a function of the plasma membrane?

a)

Signal reception

b)

Transport regulation

c)

DNA replication

d)

Mechanical protection

6.

Which is the most abundant lipid in cell membranes?

a)

Cholesterol

b)

Phospholipids

c)

Glycolipids

d)

Steroids

7.

A fatty acid with a double bond in the cis configuration will:

a)

Increase fluidity

b)

Decrease fluidity

c)

Have no effect on fluidity

d)

Convert to cholesterol

8.

Which factor decreases membrane fluidity?

a)

Short hydrocarbon chains

b)

Unsaturated fatty acids

c)

Long saturated hydrocarbon chains

d)

High temperature

9.

Cholesterol in animal membranes functions mainly to:

a)

Provide energy

b)

Stabilize fluidity

c)

Pump ions

d)

Form lipid rafts

10.

In bacteria and yeast, membrane fluidity is adjusted by:

a)

Changing cholesterol content

b)

Altering fatty acid chain length and saturation

c)

Increasing protein concentration

d)

Adding glycolipids

11.

Which of the following membranes would be most fluid?

a)

Long saturated fatty acids

b)

Long unsaturated fatty acids

c)

Short unsaturated fatty acids

d)

Short saturated fatty acids

12.

Glycolipids are found primarily:

a)

On the cytosolic side of the bilayer

b)

On the extracellular side of the bilayer

c)

Evenly distributed

d)

Only in bacteria

13.

The lipid bilayer is self-sealing because:

a)

It is held together by covalent bonds

b)

Hydrophobic interactions drive lipids to minimize water contact

c)

Proteins act as glue

d)

Carbohydrates stabilize the edges

14.

The most energetically favorable shape for a lipid bilayer is:

a)

Flat sheet

b)

Cylinder

c)

Sphere (vesicle)

d)

Cube

15.

In animal cell membranes, proteins make up roughly:

a)

5% of mass

b)

25% of mass

c)

50% of mass

d)

80% of mass

16.

A transmembrane domain typically takes the form of:

a)

β-sheet

b)

α-helix

c)

Random coil

d)

Parallel strands

17.

The amphipathic nature of transmembrane α-helices is due to:

a)

Hydrophobic side chains on one side, hydrophilic on the other

b)

Hydrophilic backbone protected by hydrogen bonding

c)

Glycosylation

d)

Covalent linkage to cholesterol

18.

Peripheral membrane proteins can be removed by:

a)

Detergents

b)

Heat denaturation only

c)

Hydrolysis of phospholipids

d)

  1. Changes in salt concentration or pH

19.

Integral membrane proteins can be solubilized using:

a)

Buffers alone

b)

High salt

c)

Detergents

d)

Proteases

20.

A detergent disrupts membranes because:

a)

It is fully hydrophilic

b)

It has amphipathic properties similar to lipids

c)

It forms hydrogen bonds only with proteins

d)

It replaces cholesterol

21.

The mobility of membrane proteins can be restricted by:

a)

Cell cortex attachment

b)

Extracellular matrix binding

c)

Cell–cell junctions

d)

All of the above

22.

Membrane fluidity is important for:

a)

Vesicle fusion

b)

Signal transduction

c)

Distribution of new proteins/lipids

d)

All of the above

23.

In epithelial cells, restricted protein movement creates:

a)

Uniform membranes

b)

Specialized membrane domains

c)

Random diffusion

d)

Symmetric lipid distribution

24.

The plasma membrane of red blood cells is supported mechanically by:

a)

Cell wall

b)

Cytoskeletal cortex

c)

Golgi network

d)

Cholesterol rafts

25.

The carbohydrate-rich layer on the outer cell membrane is called:

a)

Glycocalyx

b)

Lipid raft

c)

Peptidoglycan

d)

Cell cortex

26.

The glycocalyx is important for:

a)

DNA replication

b)

Cell recognition and protection

c)

ATP production

d)

Cytoskeleton assembly

27.

The thickness of the lipid bilayer is about:

a)

0.5–1 mm

b)

4–10 nm

c)

0.1 µm

d)

1 µm

28.

Membrane proteins make up about of the plasma membrane mass in animals.

a)

20%

b)

35%

c)

50%

d)

70%

29.

A meshwork of proteins beneath the plasma membrane of animal cells is called the:

a)

Nuclear lamina

b)

Cell cortex

c)

Lipid raft

d)

Glycocalyx

30.

Which lipid distribution enzyme flips newly synthesized phospholipids randomly?

a)

Scramblase

b)

Flippase

c)

Floppase

d)

Transferase

31.

Flippases function to:

a)

Move glycolipids extracellularly

b)

Transfer specific lipids to the cytosolic side

c)

Randomly move lipids in both directions

d)

Insert cholesterol into membranes

32.

Which of the following is a feature of lipid rafts?

a)

Increased fluidity

b)

High cholesterol and sphingolipid content

c)

Symmetric lipid distribution

d)

Absence of proteins

33.

Spherocytosis is caused by defects in:

a)

Cholesterol synthesis

b)

Glycolipid metabolism

c)

Cell cortex proteins

d)

Phospholipid synthesis

34.

Which statement is TRUE about membrane asymmetry?

a)

Lipid distribution is random

b)

Carbohydrates are mainly on the extracellular side

c)

Both sides of the bilayer have identical protein composition

d)

Cholesterol is only in the inner leaflet

35.

Which feature explains why membranes can reseal when punctured?

a)

Amphipathic lipid arrangement

b)

Protein scaffolding

c)

Glycocalyx coverage

d)

ATP-dependent enzymes

36.

Which of the following is a correct match?

a)

Scramblase – selective transfer

b)

Flippase – selective transfer

c)

Glycolipid – cytosolic side

d)

Cholesterol – only in mitochondria

37.

Why is the lipid bilayer considered a 2D fluid?

a)

Lipids rotate but cannot diffuse

b)

Lipids and proteins move laterally within the plane

c)

Lipids move freely between leaflets

d)

Proteins remain fixed while lipids move