Anatomy of the Cell

Question 1

What is the difference between a prokaryotic and a eukaryotic cell?

Answer 1

Prokaryotic cells have no nucleus and therefore their genetic material is floating freely in their cytoplasm. Eukaryotic cells have a distinct nucleus where their genetic material resides in the form of chromosomes.

Question 2

What is the structure that divides the cell from its surroundings?

Answer 2

The cell membrane or plasmalemma

Question 3

What are the 2 main substances in the cell membrane?

Answer 3

Protein and Phospholipids arranged in a lipid bilayer

Question 4

In addition to phospholipids and protein what else is present in the cell membrane?

Answer 4

Cholesterol and carbohydrates

Question 5

What kind of molecules can pass easily through the lipid bilayer and what do think is the significance of this?

Answer 5

Lipid soluble substances such as oxygen and carbon dioxide. This is significant because oxygen is required for the cellular energy production and as such needs to enter the cell by crossing the plasma membrane. Carbon dioxide is a by-product of this process and needs to leave the cell again by crossing the cell membrane.

Question 6

What are the roles of integral proteins in the cell membrane?

Answer 6

They allow substances to enter and leave the cell. Some called pores allow free access to the cell whereas others allow selective passage of specific substances.

Question 7

What is the name of the collection of sugar groups attached to the outside of cells?

Answer 7

The glycocalyx

Question 8

What is a ligand?

Answer 8

A ligand is a substance that binds to sites on the cell surface and bring about a change in that cell’s activity.

Question 9

How are flagella and cilia different. Provide examples of each in mammals.

Answer 9

Cilia exist in large numbers on the surface of cells where movement of substances is required. eg. The surface of upper respiratory epithelium to move mucus away from the lungs and in the oviduct to encourage the egg released from the ovary into the oviduct. Flagella are used to propel single cells through liquid. They are longer than cilia.
Spermatozoa have a single flagellum to propel them.

Question 10

What are the 4 components of the cytoplasm?

Answer 10

The cytosol, the cytoskeleton, organelles and inclusions.

Question 11

List the 3 main components of the cytoskeleton and briefly describe their role

Answer 11

Microtubules - An adjustable framework that anchors and allows movement of organelles.

Intermediate filaments - Internal network of strengthening cables that maintains the shape of the cell and resists external forces

microfilaments - located near the inner surface of the plasma membrane and enable the cell to change shape during division and create outpouchings and involutions

Question 12

What is the role of the centrosome?

Answer 12

Building and breaking down microtubules.

Question 13

What is the role of mitochondria?

Answer 13

They produce energy to fuel the cell.

Question 14

What cell is more likely to contain more mitochondria a skin cell or a muscle cell?

Answer 14

A muscle cell due to its high energy consumption.

Question 15

What do ribosomes do?

Answer 15

They synthesize protein.

Question 16

Where is the protein created by ribosomes distributed throughout the cytoskeleton used?

Answer 16

Within the cell.

Question 17

Where is protein synthesized by ribosomes attached to the endoplasmic reticulum used?

Answer 17

Outside the cell or in the plasma membrane.

Question 18

What is the difference between smooth and rough endoplasmic reticulum?

Answer 18

Smooth endoplasmic reticulum (ER) does not have ribosomes attached to its surface and is involved in synthesis and storage of lipids. Rough ER has ribosomes attached to its surface and is involved in protein production and distribution.

Question 19

What is the role of the golgi apparatus?

Answer 19

It modifies, packages and distributes molecules made for intracellular use or for export.

Question 20

What do lysosomes contain?

Answer 20

Enzymes used to break down nutrient molecules or cellular debris. Know as the garbage disposal vessel of the cell.

Question 21

What organs contain cells that contain peroxisomes? What do these organelles do?

Answer 21

The liver and kidneys. They are involved in detoxification of harmful substances and removal of free radicals.

Question 22

What is the role of the nucleus in the cell?

Answer 22

It contains the hereditary information that allows the cell to replicate itself and it contains the instructions for the creation of proteins required for normal cellular activity.

Question 23

What are the 4 structures that make up the nucleus?

Answer 23

The nuclear envelope or membrane​, the nucleoplasm​, chromatin​ & the nucleolus

Question 24

What structures in the nuclear envelope allow communication between the nucleus and the cytoplasm?

Answer 24

Nuclear pores

Question 25

What substances travel through the nuclear pores?

Answer 25

mRNA and rRNA move from the nucleus to the cytoplasm and proteins move in the opposite direction.

Question 26

What is the full name for DNA?

Answer 26

Deoxyribonucleic acid

Question 27

How would you describe the structure of DNA

Answer 27

A double helix. 2 strands of alternating sugar and phosphate groups joined centrally by linked nitrogenous bases

Question 28

Which part of DNA contains the information required to produce proteins?

Answer 28

The nitrogenous bases

Question 29

What are the differences between DNA and RNA?

Answer 29

DNA has 2 strands of the 4 nitrogenous bases adenine​, thymine​, guanine​ & cytosine. RNA is single-stranded and contains uracil in the place of thymine.

Question 30

What are the roles of RNA?

Answer 30

Coding RNA is the template for production of proteins. Non-coding RNA performs multiple other cellular functions such as catalysis as seen in ribosomes.

Question 31

Define Chromatin

Answer 31

It is the genetic material within the nucleus and consists of DNA and proteins called histones that are molecules that serve to keep DNA untangled and organized.