Eukaryotic Cells and Orangelles (pages 10-13)

Question 1

There are two types of cells, what are they?

Answer 1

Prokaryotic and Eukaryotic.

Question 2

What is Organelles?

Answer 2

Organelles are all they tiny bits and bobs that you can only see in detail with a fancy microscope.

Question 3

True or False,
Organisms can be Prokaryotes or Eukaryotes?

Answer 3

True.

Question 4

What is Prokaryotic Organisms?

Answer 4

they are prokaryotic cells, i.e. they’re singled-celled organisms.

(and Eukaryotic organisms are made up of eukaryotic cells).

Question 5

Explain the difference of Eukaryotic Cells and Prokaryotic Cells?

Answer 5

Eukaryotic cells are complex and include all animal and plant cells.

Prokaryotic cells are smaller and simpler, (e.g. bacteria). - see page 15 for more details.

Question 6

Prokaryotes and Eukaryotes are types of cells that contain what?

Answer 6

Organelles. (they are parts of cells - each one has a specific function).

Question 7

Are Plant and Animal Cells Eukaryotic or Prokaryotic?

Answer 7

plant and animal cells are both Eukaryotic.

Question 8

Eukaryotic cells are generally a bit more complicated than prokaryotic cells.

List what is in an Animal Cell?

Answer 8

Plasma (cell surface) membrane
rough endoplasmic reticulum
nucleolus
nucleus
smooth endoplasmic reticulum
lysosome
ribosome
nuclear envelope
golgi apparatus
cytoplasm
mitochondrion

look at diagram on page 10 (you will be expected to be able to interpret photos of cells and their organelles, tanken through different types of microscope - so make sure you learn to recognise all the structures on pages 11-13. - see diagrams

Question 9

Plant cells have the same organelles as animal cells, but with a few added extras.

Name what is in a plant cell?

Answer 9

a cell wall with plasmodemata (channels for exchanging substances with adjacent cells.
a vacuole (compartment that contains cell sap)
chloroplasts.

(all items are):

plasma (cell surface) membrane
chloroplast
rough endoplasmic reticulum
plasmodesma
mitochondrion
golgi apparatus
vacuole
smooth endoplasmic reticulum
cytoplasm
nuclear envelope
nucleolus
nucleus
ribosome
cell wall

Question 10

Describe what a Plasma (cell surface) membrane is? and draw it

Answer 10

It is inside Eukaryotic Cells

The membrane found on the surface of animal cells and just inside the cell wall of plant cells and prokaryotic cells. It’s made mainly of lipids and protein.

look at diagram on page 11 how it looks.

The plasma (cell surface) membrane has:

plasma membrane
cytoplasm.

Question 11

Explain the function of a Plasma (cell surface) membrane?

Answer 11

Regulates the movement of substances into and out of the cell. It also has receptor molecures on it, which allow it to respond to chemicals like hormones.

Question 12

Describe what a cell wall is, and how to draw one?

Answer 12

It is in Eukaryotic Cells

It is a rigid structure that surrounds plant cells. It’s made mainly of the carohydrate cellulose

see diagram on page 11 to see what it looks like

The Cell wall has the following:

plasma membrane
cell wall
cytoplasm

Question 13

what is the function of a Cell Wall?

Answer 13

It supports plant cells.

Question 14

Describe what a Nucleus is and how to draw it?

Answer 14

It is in Eukaryotic Cells

It is a large organelle surrounded by a nuclear envelope (double membrane), which contains many pores. The nucleus contains chromatin (which is made from DNA and proteins) and a structure called the nucleolus.

look at the diagram on page 11 to see what it looks like.

it has:

nuclear envelope
nucleolus
nuclear pore
chromatin.

Question 15

What is the function of the Nucleus?

Answer 15

The nucleus controls the cell’s activities (by controlling the transcription of DNA - (see page 40). DNA contains instructions to make proteins - (see page 38). The pores allow substances (e.g. RNA) to move between the nucleus and the cytoplasm. The nucleolus makes ribosomes.

Question 16

Describe what Lysosome Organelle is? and draw it?

Answer 16

It is in Eukaryotic Cells.

A round organelle surrounded by a membrane, with no clear internal structure.

see page 11 for diagram.

Question 17

What is the Function of the Lysosome Organelle?

Answer 17

it contains digestive enzymes. These are kept separate from the cytoplasm by the surrounding membrane, and can be used to digest invading cells or to break down worn out components of the cell.

Question 18

Describe what Ribosome is and how to draw it?

Answer 18

It is in Eukaryotic Cells

A very small organelle that either floats free in the cytoplasm or is attached to the rough endoplasmic reticulum. It’s made up of proteins and RNA (see page 34). It’s not surrounded by a membrane.

Look at diagram on page 11 to see how it looks, it has:

small subunit
large subunit.

Question 19

What is the function of Ribosome Organelle?

Answer 19

The site where proteins are made.

Question 20

Most organelles are surrounded by membranes, why can this cause confusion?

Answer 20

you may think that a diagram of an organelle is a diagram of a whole cell, they’re not cells - they’re parts of cells, this can cause confusion.

Question 21

Describe what Rough Endoplasmic Reticulum (RER) orgenelle is and draw it?

Answer 21

It is in Eukaryotic Cells

A system of membranes enclosing a fluid-filled space. The surface is covered with ribosomes.

Rough Endoplasmic Reticulum (RER) has the following:

Ribosome
Fluid.

Question 22

Explain the function for Rough Endoplasmic Reticulum (RER) Organelle?

Answer 22

Folds and processes proteins that have been made at the ribosomes.

Question 23

Describe Smooth Endoplasmic Reticulum (SER) organelle and draw it?

Answer 23

It is in Eukaryotic Cells

It is similar to rough endoplasmic reticulum, but with no ribosomes.

Question 24

Explain the function of Smooth Endoplasmic Reticulum (SER) organelle?

Answer 24

Synthesises and processes lipids.

Question 25

Describe what Vesicle organelle is and draw it?

Answer 25

It is in Eukaryotic Cells

A small fluid-filled sac in the cytoplasm, surrounded by a membrane.

The vesicle has the following:

Cell’s plasma membrane
vesicle.

Question 26

What is the function of Vesicle organelle?

Answer 26

Transports substances in and out of the cell (via the plasma membrane) and between organelles. Some are formed by the Golgi apparatus or the endoplasmic reticulum, whiles others are formed at the cell surface.

Question 27

Describe what Golgi Apparatus organelle is, and draw it?

Answer 27

It is in Eukaryotic Cells

A group of fluid-filled, membrane-bound, flattened sacs. Vesicles are often seen at the edges of the sacs.

see diagram on page 12

Question 28

Explain the function of Golgi Apparatus organelles?

Answer 28

It processes and ackages new lipids and proteins. It also makes lysosomes.

Question 29

Describe what mitochondrion organelles look like and draw it?

Answer 29

It is in Eukaryotic Cells.

They’re usually oval-shaped. They have a double membrane - the inner one is folded to form structures called cristae. Inside is the matrix, which contains enzymes involved in respiration.

Mitochondrion has the following (see diagram on page 12).

outer membrane
inner membrane
crista
matrix

Question 30

Explain the function of Mitochondrion organelles?

Answer 30

The site of aerobic respiration, where ATP is produced. They’re found in large numbers in cells that are very active and require a lot of energy.

(ATP is the chemical energy produced by the mitochondria is stored in a small molecule called adenosine triphosphate (ATP)).

Question 31

Describe Chloroplast organelles and draw them?

Answer 31

It is in Eukaryotic Cells.

A small, flattened structure found in plant cells. It’s surrounded by a double membrane, and also has membranes inside called Thylakoid Membranes. These membranes are stacked up in some parts of the chloroplast to form grana. Grans are linked together by lamellae - thin, flat pieces of thylakoid membrane.

Chloroplast has the following: (see diagram on page 12)

Stroma
two membranes
granum (plural - grana)
lamella (plural = lamellae)

Question 32

Explain the function of Chloroplast organelle?

Answer 32

The site where photosynthesis takes place. Some parts of photosynthesis happen in the grana, and other parts happen in the stroma (a thick fluid found in chloroplasts).

Question 33

Describe what Centriole organelle is and draw it?

Answer 33

It is in Eukaryotic cells.

Small, hollow cylinders, made of mitotubules (tiny protein cylinders). found in animal cells, but only some plant cells.

See diagram on page 13
Centriole has the following:

microtubule

Question 34

Explain the function of Centriole organelle?

Answer 34

involved with the separation of chromosomes during cell division (see page 60-62).

Question 35

Describe what Cilia organells is and draw it?

Answer 35

It is in Eukaryotic Cells.
Small, hair-like structures found on the surface membrane of some animal cells. In cross section, they have an outer membrane and a ring of nine pairs of protein microtubules inside, with two microtubles in the middle. (this is known as the ‘9 + 2’ formation).

See diagram on page 13.

Question 36

What is the function of Cilia organelle?

Answer 36

The microtubules allow the cilia to move. This movement is used by the cell to move substances along the cell surface.

Question 37

Describe Flagellum organell and draw it?

Answer 37

It is in Eukaryotic Cells
Flagella on eukaryotic cells are like cilia but longer. They stick out from the cell surface and are surrounded by the plasma membrane. Inside they’re like cilia too - two microtubles in the centre and nine pairs around the edge.

See diagram on page 13

Question 38

Explain the function of Flagellum organelle?

Answer 38

The microtubules contract to make the flagellum move. Flagella are used like outboard motors to propel cells forward (e.g. when a sperm cell swims).

Question 39

How does the structure of rough endoplasmic reticulum differ from that of smooth endoplasmic reticulum?

Answer 39

The most basic difference between RER and SER is the presence of ribosomes.

when ribosomes attach to the surface of an ER, it gives a characteristic rough appearance’ hence it is called Rough ER. On the other hand, a smooth ER does not have ribosomes on its surface. It posesses ribosomes attached to its membrane.

Question 40

Describe the function of Vesicles?

Answer 40

Transports substances in and out of the cell (via the plasma membrane) and between organelles. Some are formed by the Golgi apparatus or the endoplasmic reticulum, while others are formed at the cell surface.

Question 41

Which of the following describes a structure found in plant cells but not in animal cells?

A) a system of membranes enclosing a fluid-filled space
B) a flattened structure surrounded by a double membrane. Internal membranes are stacked up in places to form grana.
C) A small organelle consisting of two subunits. It is not surrounded by a membrane.
D) A round, membrane-bound organelle containing digestive enzymes

(1 mark)

Answer 41

answer is B (1 mark)

Question 42

Identify these two organelles from their descriptions as seen in an electron micrograph;

A)
i) an oval-shaped organelle surrounded by a double membrane. The inner membrane is folded and the projects into the inner space, which is filled with a grainy material (1 mark)

ii) a collection of flattened membrane ‘sacs’ arranged roughly parallel to one another. Small, circular structures are seen at the edges of these ‘sacs’ (1 mark)

B) State the function of the two organelles that you have identified (2 marks)

Answer 42

A)
i) Mitochondrion (1 mark)
ii) Golgi apparatus (1 mark)

B) Mitochondria are the site of aerobic respiration (1 mark)
The Golgi apparatus processes and packages new lipids and proteins/makes lysosomes (1 mark).