3.1.2 - Eukaryotic Cells

Question 1

Describe Eukaryotic Cells
(2 Points)

Answer 1

~ Have a more complex ultrastructure than prokaryotic cells.

~ E.g. Animal and plants cells.

Question 2

What Organelles Do Eukaryotic Cells Contain As Part Of Their Ultrastructure?
(7 Points)

Answer 2

~ Nucleus.

~ Mitochondria.

~ Ribosomes.

~ Endoplasmic reticulum (RER + SER).

~ Golgi apparatus.

~ Lysosome.

~ Centrioles.

Question 3

Describe The Structure Of The ‘Nucleus’ Of Eukaryotic Cells
(3 Points)

Answer 3

~ Large, separated from the cytoplasm by a double membrane called the nuclear envelope containing many pores.

~ Contains chromatin (Material chromosomes are made from).

~ Contains the nucleolus.

Question 4

Describe The Function Of The ‘Nucleus’ Of Eukaryotic Cells
(3 Points)

Answer 4

~ Controls the cells activities, by controlling the transcription of DNA.

~ Pores allow substances such as mRNA and ribosomes to move between the nucleus and the cytoplasm.

~ Nucleolus is a dark stain, which is the site of ribosome production.

Question 5

Describe The Structure Of The ‘Mitochondria’ Of Eukaryotic Cells
(2 Points)

Answer 5

~ Surrounded by a double membrane, with the inner membrane folded to form structures called cristae.

~ Inside is the matrix which contains enzymes need for aerobic respiration to produce ATP, mitochondrial DNA and ribosomes.

Question 6

Describe The Function Of The ‘Mitochondria’ Of Eukaryotic Cells
(2 Points)

Answer 6

~ Site of aerobic respiration, where ATP is produced.

~ Found in large numbers in cells and require lots of energy as they are very active.

Question 7

Describe The Structure Of The ‘Ribosomes’ Of Eukaryotic Cells
(5 Points)

Answer 7

~ Free organelles in the cytoplasm of all cells, not surrounded by a membrane.

~ Is attached to the RER.

~ Made up of proteins and RNA.

~ 8OS ribosomes are found in eukaryotic cells.

~ 7OS ribosomes are found in prokaryotic cells, mitochondria and chloroplasts.

Question 8

Describe The Function Of The ‘Ribosomes’ Of Eukaryotic Cells

Answer 8

Site where proteins are made. i.e translation.

Question 9

Describe The Structure Of The ‘RER’ Of Eukaryotic Cells
(2 Points)

Answer 9

~ Formed from folds of membrane continuous with the nuclear envelope.

~ Its surface is covered with ribosomes.

Question 10

Describe The Function Of The ‘RER’ Of Eukaryotic Cells

Answer 10

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

Question 11

Describe The Structure Of The ‘SER’ Of Eukaryotic Cells
(2 Points)

Answer 11

~ Formed from folds of membrane continuous with the nuclear envelope.

~ Its surface is not covered with ribosomes.

Question 12

Describe The Function Of The ‘SER’ Of Eukaryotic Cells

Answer 12

Synthesises and processes lipids.

Question 13

Describe The Structure Of The ‘Golgi Apparatus’ Of Eukaryotic Cells
(2 Points)

Answer 13

~ Consists of flattened sacs of membrane.

~ Vesicles are often seen at the edges of sacs.

Question 14

Describe The Function Of The ‘Golgi Apparatus’ Of Eukaryotic Cells
(2 Points)

Answer 14

~ Modifies proteins and lipids, before packaging them into Golgi vesicles.

~ Also makes lysosomes.

Question 15

Describe The Structure Of The ‘Lysosome’ Of Eukaryotic Cells
(2 Points)

Answer 15

~ Surrounded by a membrane.

~ Has no clear internal structure.

Question 16

Describe The Function Of The ‘Lysosome’ Of Eukaryotic Cells
(3 Points)

Answer 16

~ Are specialist forms of vesicles, containing digestive enzymes.

~ Kept separate from the cytoplasm by the surrounding membrane.

~ Used to digest invading cells or to break down worn out components of the cell.

Question 17

Describe The Structure Of The ‘Centrioles’ Of Eukaryotic Cells
(2 Points)

Answer 17

~ Hollow cylinders made of microtubules (Protein cylinders).

~ Not found in plants or fungi, only animal cells.

Question 18

Describe The Function Of The ‘Centrioles’ Of Eukaryotic Cells
(2 Points)

Answer 18

~ Involved with the separation of chromosomes during cell division.

~ Two centrioles at right angles to each other form a centrosome, which organises spindle fibres during cell division.

Question 19

Describe The Process Of Organelle Involvement In Protein Transport And Production
(5 Points)

Answer 19

1) Ribosomes on the RER produce proteins that can be excreted or become attached to the cell surface membrane.

Note -> Free ribosomes in the cytoplasm make proteins that stay in the cytoplasm.

2) New proteins produced at the RER are folded and processed in the RER.

3) These proteins are then transported to the Golgi apparatus via vesicles, which fuse with the Golgi apparatus releasing the proteins.

4) In the Golgi apparatus the proteins are modified and then packaged into vesicles.

5) Vesicles then fuse with the plasma membrane, secreting the proteins.