Unit Two: Dr Smith's Content

Question 1

What are Flagella and Cilia

Answer 1

• elongated motile structures that extend from cell surface
• cilia are shorter than flagella
• cilia have a greater amount
• flagellnum propel prokaryotic cells to move

Question 2

What are some structure relevant to plant cells

Answer 2

• chloroplasts
• central vacuole
• plant cell walls

Question 3

What are Plastids

Answer 3

• yellow-green in colour
• site of photosynthesis in plant cells
• plastids contain DNA genomes and machinery for gene expression + synthesis of protein on ribosomes
• some proteins within plastids are encoded by genomes/nuclear genes and imported into organelles from cytosol

Question 4

What are Chloroplasts

Answer 4

• surrounded by outer membrane and inner memebrane in the stroma
• thykaloid content
• thykaloids contain chlorphyll
• CONVERT LIGHT ENERGY

Question 5

What is the Central Vacuole

Answer 5

• large vesicles that perform specialized
• 90% or more of plant cells can be made up of central vacole
• tonoplast: surrounds the central vacuole

Question 6

What are the functions of central vacuoles

Answer 6

• supports the cell structure
• store salts, organic acid, sugars, storage proteins, pigments and waste products
• produce colours of many flowers
• contain enzymes that break down molecules
• contain molecules that provide chemical defences against pathogenic organisms

Question 7

What is the function of the Cell Wall

Answer 7

• support individual cells
• protect cells against invading bacteria and fungi
• contribute to turgor pressure produced in central vacolue
• consist of cellulose

Question 8

What is Cellulose

Answer 8

• long polymers of glucose
• most abundunt macromolecule
• aggregate into bundles (microfibrils)
• embedded into network of other polysacchardies

Question 9

What does the middle lamella do

also known as (pectin)

Answer 9

hold together walls of adjacent cells

Question 10

What is the Plasmodesmta

Answer 10

• plasma membrane lined-channels that connect the cytosols of adjacent cells
• allow ions and small molecules to move directly from one cell to another through cytosol

Question 11

What does the Plasmodesmta do

Answer 11

preforate primary and secondary cell walls

Question 12

What are some specialized animal structures

Answer 12

1. Cell adhesion molecules
2. Cell Junctions
3. Extracellular Matrix

Question 13

What are Cell Adhesion Molecules

Answer 13

• glycoproteins in plasma membrane that bind to specific molecules on other cells
• organize animal cells into tissues and organs
• provide avenues of communication

Question 14

What are Anchoring Cell Junctions

Answer 14

• form buttonlike spots, belts, that run entirely around cells
• welding adjacent cells together

most common in tissues subjected to stretching, scarring, shear, etc

Question 15

What are Desosomes

Anchoring Cell Junction

Answer 15

anchoring junctions with intermediate filaments that anchor junction in underlying cytoplasm

Question 16

What are Adherns Junctions

Anchoring Cell Junction

Answer 16

anchoring junctions with microfilaments as the anchoring cytoskeletal component

Question 17

What are Tight Cell Junctions

Answer 17

• regions of tight connections between membranes of adjacent cells
• seal spaces between cells that cover internal organs, outer surface of body, lining of internal cavities and cuts
• formed by direct fusion of proteins on outer surface

Question 18

What are Gap Junctions

Answer 18

• open direct channels that allow ions and small molecules to pass directly from one cell to another
• communicate between cells within a tissue

Question 19

What is the Extracellular Matrix (ECM)

Answer 19

• animal cells are embedded in ECM
• consits of proteins and polysaccharides secreted by cells
• forms mass of skin, bones, tendons
• provides protection and support
• affects cell division, adhesion, takes part in wound reaction

Question 20

Where is the ECM both HARD and SOFT

Answer 20

SOFT: cartilage (containing high linkage of glycoproteins)
HARD: bone (containing mineral crystals)

Question 21

What is the Cytoskeletion

Answer 21

• helps cells to maintain shape and internal organization
• support to carry out cell function

Question 22

Components of the Cytoskeleton

Answer 22

1. Intermediate Filaments
2. Microtubules
3. Actin Filaments

Question 23

What are Peroxisome

Answer 23

• single membrane organelles
• sequester diverse oxidative reactions
• play important roles in metabolism, oxygen detoxification, and signaling
• catalyze reactions, reduce oxygen