3.4 Eukaryotic cell structure

Question 1

What does the nuclear envelope do?

Answer 1

double membrane that surrounds nucleus, controls entry in and out of cell and contains reactions within it

Question 2

What do nuclear pores do? Typically how many are there?

Answer 2

• allow passage of large molecules such as mRNA
• 3000

Question 3

What does the nucleoplasm do?

Answer 3

granular, jelly-like material that makes up bulk of nucleus

Question 4

What do nucleolus do?

Answer 4

manufactures ribosomal RNA and assembles ribosomes and contains gen

Question 5

What are the functions of the nucleus?

Answer 5

• act as the control centre of the cell
• contain genetic material in form of DNA and chromosomes
• manufacture ribosomal RNA and ribosomes
• protein synthesis

Question 6

What is found around the mitochondrion?

Answer 6

double membrane

Question 7

What is the role of the cristae?

Answer 7

extensions of the inner membrane which provide a large surface area for attachment of enzymes

Question 8

What is the role of the matrix?

Answer 8

contains protein, lipids, ribosomes and DNA, many enzymes involved in respiration are found in the matrix

Question 9

What is the role of the chloroplast envelope?

Answer 9

double plasma membrane that is highly selective in what goes in and out of the cell

Question 10

What is the role of the grana?

Answer 10

stacks of up to 100 disc-like structures caller THYLAKOIDS

Question 11

What is the role of the stroma?

Answer 11

fluid-filled matrix where the second stage of photosynthesis takes place

Question 12

What is the role of the Rough Endoplasmic Reticulum?

Answer 12

• contains ribosomes
• provide large surface area for synthesis of proteins and glycoproteins
• provide pathway for transport of materials, especially proteins

Question 13

What is the role of the Smooth Endoplasmic Reticulum?

Answer 13

• lacks of ribosomes
• synthesise, store and transport lipids and carbohydrates

Question 14

What are the functions of the Golgi Apparatus?

Answer 14

• add carbohydrates to proteins to form glycoproteins
• produce secretory enzymes
• secrete carbohydrates
• transport, modify and store lipids
• form lysosomes

Question 15

What are the functions of the lysosomes?

Answer 15

• hydrolyse material ingested by phagocytosis
• release enzymes to outside of the cell
• digest worn out organelles
• completely break down cells after they have died

Question 16

What are the two types of ribosomes and where are they found?

Answer 16

• 80S, found in eukaryotic cells
• 70S, found in prokaryotic cells, mitochondria and chloroplasts

Question 17

What is the function of the cell wall?

Answer 17

• provide strength to prevent cell bursting
• give mechanical strength to plant
• allow water to pass along it