Cells

Question 1

List the organelles found in all eukaryotic cells

Answer 1

• Cell surface (plasma) membrane
• Cytoplasm
• Smooth endoplasmic reticulum
• Rough endoplasmic reticulum
• Golgi apparatus + vesicle
• Nucleus (nucleolus + nuclear envelope)
• Ribosomes
• Mitochondrion

Question 2

List organelles found in animal cells only

Answer 2

• Lysosome

Question 3

List organelles found in plant and algal cells only

Answer 3

• Chloroplasts
• Vacuole
• Cell wall
• Plasmadesmata

Question 4

Describe the function of the cell wall

Answer 4

• Maintains cell rigidity

Question 5

What is the cell wall made of in:
- plants
- algae
- fungi
- prokaryotes

Answer 5

• Cellulose
• Cellulose
• Chitin
• Murein

Question 6

Describe the function of the cell membrane

Answer 6

• Regulates what can enter and exit the cell

Question 7

Describe the function of the cytoplasm

Answer 7

• Site of anaerobic respiration
• Where chemical reactions occur

Question 8

Describe the components and function of the nucleus

Answer 8

• Nuclear envelope, Nucleolus, Chromosomes
• Contains DNA (protein instructions)
• Controls cell activity as it controls transcription
• Pores in envelope control what enters and exits nucleus
• Nucleolus synthesises ribosomes and contains ribosomal DNA

Question 9

Describe the structure and function of the Golgi apparatus

Answer 9

• Flattened fluid-filled sacs
• Transport, modify, package and sort lipids and proteins
• Labels them so they got to their suited destination

Question 10

Describe the function of the Golgi vesicle

Answer 10

• Transports modified lipids and proteins to cell surface membrane

Question 11

Describe the function of the rough endoplasmic reticulum

Answer 11

• Involved in the production of proteinsythesis
• Tubules called cisternae allow for transport of proteins

Question 12

Describe the function of the rough endoplasmic reticulum

Answer 12

• Involved in the production of proteinsythesis
• Tubules called cisternae allow for transport of proteins

Question 13

Describe the function of the smooth endoplasmic reticulum

Answer 13

• Involved in the synthesis of lipids
• Processes lipids

Question 14

Describe the function of the mitochondria

Answer 14

• Site of aerobic respiration
• Produces ATP
• Inner membrane folds to form cristae which increase cell surface area
• Contains matrix which enzymes used in photosynthesis are found
• Has its own ribosomes and DNA to quickly produce proteins

Question 15

Describe the structure and function of the chloroplast

Answer 15

• Site of photosynthesis
• Thykaloid membranes stack (up to 100) to form grana; grana can be joined by lamelle (flat thin thykaloid)
• Each grana has a chloroplast
• Stroma is weak solution of sugars and salts
• Stage 1 of photosynthesis occurs in grana (chloroplasts)
• Stage 2 of photosynthesis occurs in the stroma

Question 16

Describe the function of the ribosome and the two types

Answer 16

• Site of protein synthesis
• Either free floating in cytoplasm or attached to RER
• 80S - bigger (25nm radius), found in eukaryotic cells
• 70S - smaller; found in prokaryotic cells, mitochondria and ribosomes

Question 17

How are cells specialised

Answer 17

• Genes can be turned off
• Genes necessary for cell function are turned on (expressed)

Question 18

Describe the function of a cell wall (bacterium)

Answer 18

• Made up of murein
• Acts a physical barrier that excludes substances
• Protects against mechanical damage and osmotic lysis

Question 19

Describe the function of the capsule (bacterium)

Answer 19

• Made of slime
• Protects bacterium from other cells
• Helps group bacteria together for further protection

Question 20

Describe the function of the cell surface membrane (bacterium)

Answer 20

• Acts as a differentially permeable layer
• Controls entry and exit of chemicals

Question 21

Describe the function of ribosomes (bacterium)

Answer 21

• 70S - smaller
• Synthesis proteins

Question 22

Describe the function of Circular DNA (bacterium)

Answer 22

• Holds genetic material
• Processes genetic information for replication

Question 23

Describe the function of Plasmids (bacterium)

Answer 23

• Can reproduce themselves
• Posses genes necessary to survive adverse environments
• used as vectors in genetic engineering

Question 24

Describe the function of the flagella (bacterium)

Answer 24

• Lash like
• Propels bacteria

Question 25

Describe the difference between a gram positive and gram negative cell wall

Answer 25

- Gram-positive cell wall is thick and has multiple layers of peptidoglycan - Gram-negative cell wall consists of an outer membrane and multiple layers of peptidoglycan - Gram-negative bacteria are more resistant as their cell wall is impenetrable

Question 26

List the organelles in a bacterium cell

Answer 26

- Capsule - Cell wall - Cell surface membrane - Ribosomes - Circular DNA - Plasmids - Cytoplasm - Flagella

Question 27

Describe the process of binary fission

Answer 27

- Circular DNA replicates - both attach to cell membrane - Plasmids replicate a variable number of times - New cell membrane grows and cytoplasm begins to divide - New cell wall forms - dividing original cell into two daughter cells - Each daughter cell has one C. DNA but a variable number of plasmids

Question 28

Describe bacteria's use in industry

Answer 28

- Replicated in a fermenter - division is rapid - Cells produced is exponential - They are sources of enzymes

Question 29

Differences between DNA in a chloroplast and DNA in the nucleus

Answer 29

- C DNA is shorter , N DNA is longer - N DNA is associated with histones, C DNA isn't - C DNA doesn't have introns, D DNA does - N DNA is linear, C DNA is circular

Question 30

explain the arrangement of phospholipids in the cell surfaces membrane

Answer 30

-bilayer -hydrophilic head faces water (attracts) -hydrophobic tail faces away/ repels water

Question 31

Describe how a phagocyte destroys pathogen present in the blood

Answer 31

- detects antigen - engulfs pathogen -phagosome fuses with vesicle which releases hydrolytic enzymes