cell structure

Question 1

what is the difference between prokaryotes and eukaryotes?

Answer 1

prokaryotes have no nucleus and membrane bound organelles, eukaryotes do.
prokaryotes are significantly smaller in size compared to eukaryotes.

Question 2

describe the structure and function of the nucleus.

Answer 2

• surrounded by nuclear envelope, nuclear pores allow mRNA out.
• contains genetic info which codes for proteins.
• site of transcription - producing mRNA.
• nucleolus makes ribosomes.
• has a double membrane.

Question 3

describe the structure and function of mitochondria.

Answer 3

• has double membrane.
• where cellular respiration occurs and ATP is generated.

Question 4

describe the function of lysosomes.

Answer 4

releases hydrolytic enzymes to break down pathogens.

Question 5

describe the structure and function of ribosomes.

Answer 5

• two subunits made of rRNA and proteins
• either free in cytosol or attached to endoplasmic reticulum/
• protein synthesis

Question 6

describe structure and function of endoplasmic reticulum.

Answer 6

• two types: rough and smooth
• membrane synthesis and metabolic processes.

Question 7

describe structure and function of golgi apparatus and vesicles.

Answer 7

golgi apparatus - flat membrane sacs, modifies lipids and proteins and produces lysosomes.
vesicles - small membrane sacs, transports lipids and proteins.

Question 8

describe the structure and function of cell surface membrane.

Answer 8

• made of lipids and proteins.
• controls the passages of substances in and out of the cell.

Question 9

list the seven components of the structure of a chloroplast.

Answer 9

inner membrane
outer membrane
inter membrane space
stroma lamellae
thylakoid
granum
stroma

Question 10

what is the thylakoid and what’s it for?

Answer 10

• flattened fluid-filled sacs/discs
  the thylakoid allows substances in and out of the chloroplast.
• these thylakoids stack up to form structures known as grana.
• thylakoid membranes have a pigment on their outer surface called chlorophyll which absorbs light during photosynthesis.

Question 11

what are grana connected by?

Answer 11

grana are connected by membraneous channels called stroma lamellae which ensure the stacks of thylakoids are connected but distanced from each other.

Question 12

what is the fluid found in the inner membrane of chloroplasts called? where else can it be found?

Answer 12

stroma - the space outside the thylakoid space is also called the stroma.

Question 13

what is found floating in the stroma?

Answer 13

DNA
ribosomes
strach granules
proteins

Question 14

what’s the structure and function of the membranes of a chloroplast

Answer 14

inner membrane - forms a border to the stroma, it regulates the passage of materials in and out the chloroplast - fatty acids and lipids are synthesised.
outer membrane - its a semi porous membrane and is permeable to small molecules and ions which diffuse easily (not permeable to larger proteins).
inter membrane space - a thin space between the inner and outer membrane.

Question 15

what is the function of the pili?

Answer 15

reproduction of prokaryotic cells, attach to other bacterial cells

Question 16

what does the cell wall of a prokaryotic cell contain?

Answer 16

glycoprotein of DNA

Question 17

what’s the function of the capsule in prokaryotes?

Answer 17

for protection, retains moisture

Question 18

what does the stroma contain?

Answer 18

thylakoid membrane
70S ribosomes
circular DNA
starch granules/lipid droplets