Cell Biology

Question 1

Organelles

Answer 1

nucleus, ribosomes, endorplasmic reticulum, golgi apparatus, vesicles, vacuoles, lysosomes, mitchondria, chloroplsts, centrioles

Question 2

Membrane

Answer 2

encloses cell

selective permiable

fluid mosiac model: phosphlipid bilayer + freely moving proteins

phospholipid bilayer: hydrophillic phosphate heads, hydropphobic fatty acid chains

small charged particles pass through freely, larger charged molecules require carrier protein

Question 3

Animal vs plant cell

Answer 3

Plant: no centromere (centrioles)

cell wall –> cellulose

chloroplasts–> photosynthesis

no lysosomes

mature cells: large vacule

Question 4

Nucleus

Answer 4

Controls activity of cell (cell division)

surrounded by nuclear membrane

CONTAINS:

DNA: w/ histones (strucutral proteins)- forms chromosomes

nucleolus( rRNA synthesis),

“control center”

Question 5

Endoplasmic reticulum

Answer 5

network of memebrane

transports materials throughout cell (excretion)

Question 6

Golgi apparatus

Answer 6

recieves vesicles from smooth ER

modifies vesicles

repackages vesicled and distributes to cell surface (exocytosis)

“packaging center”

Question 7

Mitochondria

Answer 7

Energy supply

aerobic respiration

2 (outter and inner) phosphlipid bilayer

Question 8

cytoplasm

Answer 8

metabolic activity

transport within cyclosis

Question 9

Vacuoles/Vesicles

Answer 9

Membrane bound sacs involved in transport/storage of materials that are ingested, secreted, rocessed or digested by cell

vacuoles>vesicles

vacuoles more likely to be found in plants

Question 10

Centrioles

Answer 10

Spindle organization during cell division. not bound by memberane

only found in animals in centrosome

Question 11

Lysosomes

Answer 11

membrane bound vesicles w/ enzymes- intracellular digestion- breaks down materials

Question 12

Autolysis

Answer 12

INjuered/dying tissue “commits suicide” by rupturing lysosome membrane, releasing hydrolytic enzymes

Question 13

Cytoskeleton

Answer 13

supports cell by mainting shape- cell mobility

microtubules, microfiliments, intermediate filaments

microtubules: hollow rods provide support. make up centrioles

cilia/flagella: arrangments of microtubules that extend from cells and involved in mobility and movement

microfiliaments: actin rods. move materials across plasma membrane

Question 14

Transport

Answer 14

Diffusion:Dissolved particles down concentration gradient (high concentration to low)

Osmosis: diffusion of H20 from low solute concentration to high solute concentration (high concentration h20 to low concentration h20)

Hypertonic: cytoplasm has lower solute concentration than cell. cell shrinks

Hypotonic: cell has lower solute concentration than cytoplasm. cell grows

facilitated diffusion: passive transport- down concentration through channels or carrier proteins (no energy)

active transport: net movement of particles against concention gradient w/ transport proteins (energy required)

symporters: move 2 or more ions/molecules
antiporter: exchange of 1 or more ion/molecule for another
pumps: energy dependent carriers (ATP)
endocytosis: cell membrane enters, and forms vesicle contain extracellular medium
pinocytosis: ingestion of fluids/small fluids
phagocytosis: engulfing large particles
exocytosis: vesicle in cell fuses with cell membrane and relases contents to the outside- cell growth, itracellular signalling

Question 15

Circulation

Answer 15

definition: transportation of material w/ in cells throughout body

Intracellular circulation:

brownian movement: KE spreads small particals though cytoplasm

cyclosis/streaming: circular motion of cytoplasm around cell transport molecules

ER: provides channels through cytoplasm. dircet passage way from plasma membrane to nuclear membrane

Extracellular circulation:

diffusion: transports food/oxygen from inside to outside cell

circulatory system: used when cells are too far from outside envionment to use diffusion. uses vessels to transport fluid and pump to drive circulation