Cells - Organelles

Question 1

Structure of smooth endoplasmic reticulum

Answer 1

• Made of tubular sacs of cisternae
• No ribosomes

Question 2

Function of smooth endoplasmic reticulum

Answer 2

Synthesis and transportation of lipids, steroids hormones

Question 3

Structure of Golgi Apparatus

Answer 3

• made of flattened sacs of cisternae
• swollen ends of cisternae
• no ribosomes
• close to RER
• many layers
• presence of Golgi vesicles

Question 4

Function of Golgi Apparatus

Answer 4

• MODIFIES into lysosomes, by folding into tertiary protein or by adding a carbohydrate chain to make glycoprotein (and transported to cell membrane)
• PACKAGES into vesicles, by exocytosis (and delivered)

Question 5

Function/purpose of microvilli

Answer 5

Increase surface area of cell surface membrane - for more efficient absorption and secretion

Question 6

Structure and location of microvillli

Answer 6

Finger-like extensions of cell surface membrane found in animal cells

Question 7

Function of centrioles and microtubules

Answer 7

• Involved in nuclear division - produce spindle fibres which move and position the chromosome
• form centrosome

Question 8

Arrangement of centrioles and microtubules

Answer 8

9+2 arrangement of microtubules
- 2 centrioles arranged at 90˚
- each has 9 paired microtubules

Question 9

Function of chloroplasts

Answer 9

Photosynthesis

Question 10

Structure of chloroplasts

Answer 10

• double membrane, inner is folded into lamellae
• contains stroma and grana

Question 11

Location and function of lamellae

Answer 11

• Inner membrane of chloroplasts
• controls entry and exit of substances in and out of the chloroplast

Question 12

Function of stroma

Answer 12

(In chloroplasts)
contains circular DNA, 70S ribosomes and enzymes for light-independent stage (of photosynthesis)

Question 13

Structure and Function of grana

Answer 13

(In chloroplasts)
- Made of flattened sacs of thylakoid membranes
- carry out light-dependent stage (of photosynthesis)

Question 14

Structure of rough endoplasmic reticulum + where is it commonly found?

Answer 14

Large surface area
- made of flattened sacs of cisternae

Commonly found attached to nuclear envelope

Question 15

Function of rough endoplasmic reticulum

Answer 15

Synthesis of proteins made by ribosomes (translation)
- transported by exocytosis in vesicles to Golgi apparatus

Question 16

Function of cell wall

Answer 16

• Enclose, support and protect cell
• Provide turgidity of the cell

Question 17

Structure of cell wall

Answer 17

• made of cellulose
• fully permeable
• contains plasmodesmata (connect cytoplasm and adjacent cells)

Question 18

Function of vacuole

Answer 18

• holds cell sap
• holds ions, water, salts, waste products
• pushes chloroplasts to edge of cell
• gives turgidity, prevents cell from bursting when filled with water
• photosynthesis because of water present
• hydrolysis reactions - water present

Question 19

Structure of vacuole

Answer 19

• surrounded by tonoplast - selectively permeable membrane

Question 20

Function of tonoplast

Answer 20

Controls exchange between vacuole and cytoplasm

Question 21

Structure of nucleus

Answer 21

contains genetic information in form of DNA
- present as loosely coiled threads (chromatin)

Question 22

Function of nucleus

Answer 22

• transcription for mRNA production
• manufacturing of rRNA
• nucleolus, makes ribosomes
• nuclear envelope with nuclear pores (100nm d) —> Allie’s entry and exit of ribosomes + mRNA for compartmentalisation
• outer membrane continuous with RER

Question 23

Function of lysosomes

Answer 23

• transport, modifies and stores lipids
• involved in autolysis and autophagy
• kill bacteria - fuses with vacuole, lysozyme released by exocytosis

Question 24

What do lysosomes contain?

Answer 24

• concentrated hydrolysis enzymes
• it is a vesicle containing lysozyme (digestive protein)

Question 25

Examples of hydrolysis enzymes

Answer 25

Protease, lipase

Question 26

What are lysosomes made by

Answer 26

Golgi Apparatus and RER

Question 27

Organelles in animal cells, not present in plant cells

Answer 27

- flagella - cilia - centriole - microvilli - lysosomes

Question 28

Function of mitochondria

Answer 28

Aerobic respiration and ATP synthesis (from carbs)

Question 29

Structure of mitochondria

Answer 29

Double membrane - inner - folded to form cristae (larger SA for attachment of stalked particles containing ATP synthase enzymes) - outer - control entry + exit of materials Matrix contains small circular DNA and 70S

Question 30

Organelles present in plant cells

Answer 30

- cell wall made of cellulose - plasmodesmata - tonoplast - large permanent vacuole - chloroplasts

Question 31

Function of ribosomes

Answer 31

Translation - protein synthesis —> makes collagen

Question 32

What are ribosomes made of?

Answer 32

- Protein and rRNA - small and large subunits

Question 33

Where are 70S ribosomes found?

Answer 33

Prokaryotes, mitochondria, chloroplasts

Question 34

What subunits are 70S ribosomes composed of?

Answer 34

50S and 30S

Question 35

Where are 80S ribosomes found?

Answer 35

Eukaryotic cells

Question 36

What subunits are 80S ribosomes composed of?

Answer 36

60S and 40S

Question 37

What do plant vacuoles contain?

Answer 37

- hydrolase and act as lysosomes - some plants have secondary metabolites (stored in vacuole)

Question 38

Structure of cilia

Answer 38

Hair-like projections made from microtubules

Question 39

Function of cilia

Answer 39

Allows the movement of substance over the cell surface

Question 40

Structure of flagella

Answer 40

Hair-like projections made of longer microtubules

Question 41

Function of flagella

Answer 41

Contract to provide cell movement