2.4, 2.5, 2.6: Animal Cell Structure

Question 1

What is the definition of a cell?

Answer 1

The basic unit of all living things

Question 2

What is a eukaryotic cell?

Answer 2

A cell that contains a nucleus and makes up multicellular organs

Question 3

What kind of organisms contain eukaryotic cells?

Answer 3

Fungis, animals and plants.

Question 4

Where is the nucleolus?

Answer 4

Within the nucleus

Question 5

Describe the nucleolus (i.e what is it made of, does it have a membrane)

Answer 5

An organelle that doesn’t have a membrane, made up of DNA, RNA and proteins.

Question 6

Describe the role of the nucleolus

Answer 6

Makes RNA

Question 7

How are ribosomes produced?

Answer 7

The nucleolus makes RNA, which is used to produce Ribosomal RNA (rRNA), which is combined with proteins to form the ribosomes.

Question 8

Describe the nucleus (what does it contain, is it membranous?)

Answer 8

• Contains DNA molecules
• Surrounded by a nuclear envelope composed of two membranes

Question 9

Describe the role of DNA in the cell

Answer 9

• DNA controls metabolic activities of the cell
• DNA codes for proteins

Question 10

Where is DNA contained in the nucleus?

Answer 10

In the nuclear envelope

Question 11

What does the nuclear envelope contain to allow molecules to move in and out of the nucleus?

Answer 11

Nuclear pores

Question 12

What is the role of nuclear pores?

Answer 12

Within the nuclear envelope to allow molecules to move in and out of the nucleus

Question 13

How are chromosomes created?

Answer 13

-DNA associates with HISTONES to form CHROMATIN
-The chromatin coils and condenses to form chromasomes.

Question 14

What are histones?

Answer 14

Proteins found in the nucleus that provide structural support for chromosomes

Question 15

What is chromatin?

Answer 15

Condensed DNA, made from DNA and proteins that will make the chromosomes

Question 16

How does DNA leave the nucleus for protein synthesis?

Answer 16

Because DNA is too large to leave the nucleus, it is transcribed into RNA molecules which can leave via the nuclear pores.

Question 17

Why is DNA transcribed into RNA molecules?

Answer 17

Because the DNA is too large to leave the nucleus.

Question 18

What are the mitochondria and their function?

Answer 18

• Produce ATP
• Contain their own DNA (mtDNA)
• Can produce their own enzymes and reproduce themselves.

Question 19

What are Cristae?

Answer 19

The structures formed by the highly folded inner membrane of a mitochondrion.

Question 20

What is the number of mitochondria in the cell a reflection of?

Answer 20

The amount of energy it uses.

Question 21

Describe the structure of mitochondria.

Answer 21

-Mitochondria have a double membrane.
-Inner membrane is highly folded to form structures called CRISTAE
-The fluid interior is called the MATRIX.
-Inner membrane forming the cristae contains the enzymes used in aerobic respiration.

Question 22

How does the highly-folded inner membrane of a mitochondrian help it to perform its function?

Answer 22

Highly folded = high surface area, so more space for ATP synthesis

Question 23

What is the matrix?

Answer 23

The fluid interior of a mitochondrion

Question 24

Describe the structure of a vesicle.

Answer 24

• Membranous sacs
• A single membrane with fluid inside

Question 25

What is the role of a vesicle?

Answer 25

To transport and store materials

Question 26

What are lysosomes?

Answer 26

Specialised forms of vesicles that contain hydrolytic enzymes that break down molecules

Question 27

What is the role of a lysosome?

Answer 27

* Break down waste material in cells * Break down pathogens ingested by phagocytes

Question 28

What is the cytoplasm?

Answer 28

* The medium for metabolic processes * Contains enzymes and cytosol

Question 29

What chemical do you use to stain DNA?

Answer 29

Methylene blue

Question 30

What is the cytoskeleton?

Answer 30

A network of fibres necessary for the shape and stability of a cell

Question 31

What is the function of the cytoskeleton?

Answer 31

-Holds organelles in place, -Controls cell movement and movement of organelles within cells.

Question 32

What are the 2 key components of the cytoskeleton?

Answer 32

Microfilaments and microtubules

Question 33

What are microfilaments?

Answer 33

-A component of the cytoskeleton -Made from actin -Responsible for cell movement

Question 34

What is cytokinesis?

Answer 34

Where the cytoplasm is divided to form 2 daughter cells

Question 35

What is actin?

Answer 35

Protein that forms microfilaments in the cytoskeleton

Question 36

What are microtubules?

Answer 36

* A component of the cytoskeleton * Made of tubilin * Transport cell contents/organelles

Question 37

What does movement of the cytoskeleton by actin filaments cause?

Answer 37

Causes muscle cells to contract and allows cells to move.

Question 38

Which organelles are involved in protein synthesis?

Answer 38

The nucleus, ribosomes, rough endoplasmic reticulum, and the golgi apparatus

Question 39

What is the endoplasmic reticulum? (Structure, location, types)

Answer 39

* A network of membranes enclosing flattened sacs called cisternae. * Connected to the outer membrane of the nucleus * Made up of two types: Smooth endoplasmic reticulum and rough endoplasmic reticulum.

Question 40

What does the Rough Endoplasmic Reticulum do?

Answer 40

-Synthesises proteins -Transports proteins made on attached ribosomes

Question 41

What does the Smooth Endoplasmic Reticulum do?

Answer 41

-Is responsible for lipid and carbohydrate synthesis, and storage

Question 42

What are the two types of endoplasmic reticulum?

Answer 42

Rough Endoplasmic Reticulum and Smooth Endoplasmic Reticulum

Question 43

What is the golgi apparatus?

Answer 43

A stack of membrane bound, flattened sacs

Question 44

What is the function of the golgi apparatus?

Answer 44

Modifies proteins and "packages" them into vesicles (either vesicles if they leave the cell, lysosomes if they stay in the cell)

Question 45

What are ribosomes? (What are they made from, where, location, etc.)

Answer 45

-Manufactured in the nucleolus from rRNA and protein -The site of protein synthesis -Can be free-floating in the cytoplasm or attached to ER, forming Rough ER.

Question 46

What is the function of a ribosome?

Answer 46

* They are the site of protein synthesis * Act as an assembly line to use mRNA to assemble proteins

Question 47

How is Rough Endoplasmic Reticulum produced?

Answer 47

-Ribosomes are attached to endoplasmic reticulum

Question 48

List the stages of protein production.

Answer 48

* Proteins are synthesised on the ribosomes bound to the endoplasmic reticulum * They then pass into its cisternae and are packaged into vesicles * Vesicles containing the newly synthesised proteins move towards the Golgi Apparatus through the cytoskeleton * Vesicles fuse with the face of the Golgi Apparatus and the proteins enter * The proteins are structurally modified before leaving the Golgi Apparatus in vesicles from the opposite side

Question 49

Can animal cells have vacuoles?

Answer 49

Yes, but they are small and transient.

Question 50

What did eukaryotic cells evolve from?

Answer 50

Less complex prokaryotic cells

Question 51

What is the eukaryote equivalent of flagella?

Answer 51

Cilia

Question 52

What are cisternae?

Answer 52

Flattened membrane-bound sacs in the endoplasmic reticulum and golgi apparatus