Cell Strucutres

Question 1

Definition of a eukaryotic cell

Answer 1

Any cell or organism that possesses a clearly defined nucleus

Question 2

Define prokaryotic cells

Answer 2

No nucleus, no membrane bound organelles

Question 3

Define organelle

Answer 3

A structure within a cell that has a specific function. Most are bound with a membrane

Question 4

Give the structure and function of the nucleus

Answer 4

• structure surrounded by a double membrane (nuclear envelope) with pores in. Contains nucleolus (where ribosomes are made) and DNA in the form of chromosomes
• function controls cells activities by controlling transcription. Contains genetic material

Question 5

Give the structure and function of the Rough Endoplasmic recticulum

Answer 5

• structure a tubular system of membrane bound sacs enclosing a fluid filled space. Surface covered by ribosomes.
  -function proteins made by ribosomes on surface are folded and transported

Question 6

Give the structure and function of ribosomes

Answer 6

-structure made of ribosomal RNA and protein. Has a large and small subunit. They are a larger size in eukaryotes (80s) than prokaryotes (70s)
-function site of protein synthesis

Question 7

Give the structure and function of the smooth endoplasmic recticulum.

Answer 7

-structure a tubular system of membrane bound sacs enclosing fluid-filled space.
-function synthesises and processes lipids

Question 8

Give the structure and function of mitochondria

Answer 8

-structure double membrane. Inner membrane is folded forming cristae matrix. Contains some DNA and proteins/enzymes for respiration
-function site of aerobic respiration. Produces ATP

Question 9

Give the structure and function of the Golgi Body/Apparatus

Answer 9

-structure fluid filled membrane-bound flattened sacs. Vesicles bud of from the edges of the sacs
-function processes and packages (in a vesicle) proteins and lipids for secretion. Also creates lysosomes.

Question 10

Give the structure and function of lysosomes

Answer 10

-structure round organelle, a type of Golgi vesicle. Contains digestive enzymes called lysozymes.
-function digests old, worn out organelles or foreign cells

Question 11

Give the structure and function of vesicles

Answer 11

-structure fluid filled sac containing large molecules e.g. lipids/proteins.
-function carries molecules around the cell, from one organelle to another or into the cell from the outside, or to the cell membrane for secretion out of the cell.

Question 12

Give the structure and function of centrioles

Answer 12

-structure composed of 9 tubes each with 3 tubules
-function produce spindle fibres during mitosis and meiosis which the chromosomes attach to

Question 13

Give the structure and function of chloroplasts

Answer 13

-structure double membrane. Inside, stacks of membranes called thylakoids which make up a granum. Linked to other grana via intergranal lamellae
-function site of photosynthesis

Question 14

Give the structure and function of vacuole

Answer 14

-structure large membrane-bound sac containing cell sap
-function maintains pressure inside the cell, isolated unwanted chemicals inside the cells

Question 15

Give the structure and function of flagellum

Answer 15

-structure long thin extension from cell membrane
-function more commonly found in single-called organisms. Enables cell to propel along

Question 16

Give the structure and function of the cell membrane

Answer 16

-structure regulates movement of substances into and out of the cell
-function formed of phospholipids, cholesterol, proteins channels, carriers and receptors

Question 17

Give the structure and function of the cell wall

Answer 17

-structure in plants made of cellulose, in fungi made of chitin, in prokaryotes made of murein
-function prevents cell from bursting when it absorbs water through osmosis

Question 18

Compare and contrast the features of eukaryotic and prokaryotic cells

Answer 18

• Eukaryotes have a nucleus, prokaryotes do not
• eukaryotes have 80s ribosomes, prokaryotes have 70s ribosomes
• eukaryotes have membrane-bound organelles, prokaryotes have no membrane-bound organelles
• eukaryotes have DNA in the nucleus, prokaryotes have circular DNA
• eukaryotes have DNA associated with proteins (packaged into chromosomes), prokaryotes have DNA not associated with proteins (not packaged into chromosomes)
• eukaryotes have no plasmids, prokaryotes have plasmids
• in eukaryotes only plant and fungi cells have cell walls, prokaryotes all have a cell wall made from murein

Question 19

Describe a virus structure

Answer 19

• A-cellular, non living structures
• smaller than bacteria
• contains Nucleic acid (DNA or RNA)
• can only multiply in host cells
• Nucleic acid enclosed within a protein coat (capsid)

Question 20

Define the function of each of these components, RNA, Capsid, Lipid envelope, attachment proteins, reverse transcriptase.

Answer 20

-RNA template for DNA formation
-capsid protect the RNA
-lipid envelope fuses with host cell membrane
-attachment proteins identify host cell enables virus to attach to host cell
-reverse transcriptase enzyme that uses RNA template to make DNA