2.1.1 - Cell Structure (set C - Prokaryotic Cells )

Question 1

Explain how the flagella of prokaryotes is different to eukaryotes?

Answer 1

Flagella is thinner and does not have the 9 + 2 arrangement

• the energy supplied to rotate the filagament that forms the flagellum is supplied from the process of chemiosmosis rather then ATP

Question 2

Explain the structure of prokaryotic cells?

Answer 2

Always unicellular with relatively simple structures - DNA is not contained within the nucleus and they have very few organelles which are not-membrane bound

Question 3

Explain the difference in the way prokaryotic and eukaryotics divide cellularly?

Answer 3

Prokaryotic cells reproduce via binary fission - while eukaryotic cells reproduce via mitosis and meiosis

Question 4

How does the DNA differ in eukaryotics and prokaryotics?

Answer 4

Prokaryotes DNA is circular and double-stranded and generally only have one molecule of DNA, a supercoiled chromosome (so its more compact)

Eukaryotes DNA is also double-stranded but is linear

Question 5

Explain the difference in ribosomes in prokaryotes and eukaryotes?

Answer 5

Ribosomes in prokaryotes are smaller and are 70s - eukaryotes proteins are larger and designated 80s

• both necessary for protein synthesis but the larger 80s are involved in more complex proteins

Question 6

Exlplain how the cell wall differs in eukaryotes and prokaryotes?

Answer 6

Prokaryotic cells have a cell wall made from peptidoglycan (a complex polymer formed from amino acids and sugars)

• eukaryotes cell walls are made of cellulose

Question 7

Explain the structure of DNA in eukaryotes?

Answer 7

DNA present within nucleus and exists as multiple chromosomes which are super coiled and wrap around histones (proteins) forms a complex known as chromatin

Chromatin coils and condenses to form chromosomes

Question 8

What is the cell wall of prokaryotes made up off?

Answer 8

Composed of peptidoglycan - provides support and protection for the cell

• polymer made of amino acids and sugars

Question 9

Are mitochondria present in prokaryotes?

Answer 9

No mitochondria present, they are present in eukaryotes

Question 10

Are the endoplasmic reticulum present in prokaryotes?

Answer 10

No - only eukaryotes have smooth and rough endoplasmic reticulums

Question 11

Are lysosomes present in prokaryotes?

Answer 11

No lysosomes present - due to the fact they are formed by the endoplasmic reticulum

Question 12

Give and example of prokaryotes?

Answer 12

Bacteria and archaea

Question 13

Give an example of eukaryotic cells?

Answer 13

Animials and plants

Question 14

How is DNA wrapped around proteins in eukaryotes?

Answer 14

Eukaryotes wrap their DNA around proteins called histones

Question 15

How is DNA wrapped around proteins in prokaryotes?

Answer 15

• Multiple proteins act together to fold and condense prokaryotic DNA
• folded DNA is organised into a variety of conformations (that are supercoiled and wound around proteins)

Question 16

Is the Golgi apparatus present in prokaryotes?

Answer 16

No - the Golgi apparatus is absent in prokaryotic cells

Question 17

Explain what eukaryotic and prokaryotic cells both have?

Answer 17

• cell membrane
• cytoplasm
• ribosomes

Question 18

Do prokaryotic cells have mitochondria?

Answer 18

Prokaryotes lack mitochondria and instead produce their ATP on their cell surface membrane

• mitochondria are membrane bound organelle therefore not present