cell structure

Question 1

Which organelles are in a plant cell but not in an animal cell?

Answer 1

Cell wall
vacuole (permanent with cell sap)
chloroplast

Question 2

Describe the plasma membrane.

Answer 2

it is the membrane on the surface of animal cell but inside the cell wall of plant and prokaryotic cells

Question 3

What is the function of the plasma membrane?

Answer 3

• It regulates the movement of substances in and out of the cell
• has receptor molecules which allow it to respond to chemicals such as hormones

Question 4

Describe the cell wall

Answer 4

• a rigid structure that surrounds plant cells

- it is mainly made of cellulose (carbohydrate) or chitin (also carbohydrate)

Question 5

What is the function of the cell wall?

Answer 5

supports plant cells

Question 6

Describe lysosomes

Answer 6

• round organelle surrounded by a membrane with no clear internal structure
• contains digestive enzymes
• membrane separates organelle content from cytoplasm

Question 7

What is the function of lysosomes?

Answer 7

digests invading cells or breaks down work out cell components

Question 8

Describe ribosomes

Answer 8

small organelle that floats freely in the cytoplasm or is attached to the RER

Question 9

What is the function of ribosomes?

Answer 9

site of protein synthesis

Question 10

Describe the SER

Answer 10

sheet like membranes enclosing a fluid filled space throughout the cell

Question 11

What is the function of the SER?

Answer 11

synthesis and processes lipids

Question 12

Describe the RER

Answer 12

• sheet like membranes enclosing fluid filled space throughout the cell
• surface covered with ribosomes

Question 13

What is the function of the RER?

Answer 13

folds and processes proteins made at the ribosomes

Question 14

Describe the nucleus

Answer 14

• large organelle surrounded by nuclear envelope

- nucleus contains nucleolus and chromatin

Question 15

What is the function of the nucleus?

Answer 15

• controls genetic material

- controls cell activity

Question 16

Describe chromatin

Answer 16

made up of proteins and DNA

Question 17

What is the function of chromatin?

Answer 17

controls cell activity

Question 18

What is the function of nuclear pores?

Answer 18

allow large molecules like mRNA to exit the nucleus

Question 19

Describe the nuclear envelope

Answer 19

a double membrane surrounding the nucleus with pores

Question 20

What is the function of the nuclear envelope?

Answer 20

controls the entry and exit of materials from the nucleus

Question 21

What is the function of the nucleolus?

Answer 21

synthesis ribosomes

Question 22

Describe vesicles

Answer 22

small fluid-filled sacs in the cytoplasm surrounded by a membrane

Question 23

What is the function of vesicles?

Answer 23

transports materials in and out of the cell via cell surface membrane where fusion happens.

• During fusion contents are released out of the membrane by exocytosis
• when contents are taken in from the membrane, it is called endocytosis

Question 24

Describe the Golgi Apparatus

Answer 24

an organelle that contains membrane-bound, flattened sacs with surrounding vesicles

Question 25

What is the function of the Golgi Apparatus?

Answer 25

processes, modifies and packages proteins and lipids into vesicles - also makes lysosomes

Question 26

Describe the mitochondria

Answer 26

oval shaped organelle with a double membrane

Question 27

What is the function of the mitochondria?

Answer 27

- involved in aerobic respiration - responsible for the production of ATP molecules which carry energy - outer membrane controls the flow of materials in and out of the mitochondria

Question 28

Describe the cristae

Answer 28

extensions of the inner membrane in mitochondria

Question 29

What is the function of cristae?

Answer 29

increase the surface area for the attachment of enzymes

Question 30

Describe the matrix

Answer 30

fluid filled space in the middle of the mitochondria | - contains lipids, trace DNA and enzymes for respiration

Question 31

Describe centrioles

Answer 31

- small, hollow cylinders of microtubules | - in all animal cells and some plant cells

Question 32

What is the function of centrioles?

Answer 32

involved in the separation of chromosomes during cell division

Question 33

Describe the cilia

Answer 33

small, hair-like structures on the plasma membrane of some animal cells

Question 34

Describe the chloroplast

Answer 34

- small, flattened structure with stacks of membranes (thylakoid membranes) - surrounded by double membrane

Question 35

What is the function of chloroplast?

Answer 35

- site of photosynthesis - some parts happen in grana (stacks of thylakoid membranes) - some parts happen in the stroma (thick fluid found in chloroplasts)

Question 36

What are the 4 functions of cytoskeleton?

Answer 36

- microtubules and microfilaments support the cells organelles keeping them in their positions - helps strengthen the cell and maintain its shape - responsible for the transport of organelles and materials within the cell - proteins in a cytoskeleton also cause the cell to move e.g. propel forward

Question 37

Describe a microtubule

Answer 37

a tiny protein cylinder

Question 38

Describe a microfilament

Answer 38

a very thin protein strand

Question 39

Describe prokaryotes

Answer 39

single-celled organisms with no nucleus or few/no membrane bound organelles

Question 40

Describe eukaryotes

Answer 40

they have cells with a nucleus and many membrane bound organelles

Question 41

What are the features of a prokaryote

Answer 41

- extremely small in size - circular DNA - no nucleus - few/no membrane bound organelles - cell wall of a polysaccharide - 70s ribosomes - flagella of flagellin

Question 42

What are the features of an eukaryote

Answer 42

- large cells - linear DNA - nucleus present - many membrane bound organelles - cellulose cell wall in plants and chitin cell wall in fungi - 80s ribosomes - flagella of microtubules

Question 43

Briefly explain protein synthesis

Answer 43

- mRNA leaves nucleus and either travels to the ribosomes attached to RER or floats freely in cytoplasm - ribosomes on RER produce proteins which are folded processed and packaged into vesicles to the Golgi - Golgi modifies the proteins which are then packaged in vesicles - vesicles fuse with the plasma membrane via exocytosis to release contents outside cell or are inserted into the membrane