cell test

Question 0

WHAT is the function of the ell membrane?

Answer 0

also called plasma membrane
protects and supports the cell
controls what enters and leaves the cell
it is a lipid bilayer (2 LAYERS OF FAT CELLS)
found in all types of cells- prokaryotes and eukaryotes

Question 1

What is an organelle?

Answer 1

specialized subunits of cells that have a particular function
prokaryotes have a few
eukaryotes have many, usually surrounded by a membrane
this where we get the term “membrane-bound organelles”

Question 2

What is the function of the cell wall? (plants)

Answer 2

found in eukaryotic plant and protist cells; also in prokaryotes
main function is protection, rigidity, and support
outside of cell membrane
made of cellulose (A CARB)
allows water and dissolved substances to pass through

Question 3

What is the function of the nucleus?

Answer 3

controls most activities in the cell
usually one per cell
contains DNA the coded instructions for making proteins and other molecules for the cell
the nuclear envelope has nuclear pores,, where things can enter or leave

Question 4

What is the function of the nucleolus?

Answer 4

small, dense region in the middle of the nucleus

this is where ribosomes are formed

Question 5

What is the function of the cytoplasm?

Answer 5

clear fluid within cell that contains all organelles

moves materials throughout the cell

Question 6

What is the function of the ribosomes?

Answer 6

makes proteins in the cell
may be free in cytoplasm or attached to ER
proteins are vital to life-all cells must produce them

Question 7

What is the function of the Golgi apparatus (body)?

Answer 7

stacks of membranes used for storing, modifying, or packaging chemicals
packaged chemicals can be stored inside the cell or secreted outside the cell
cells that make saliva or mucus have many Golgi bodies

Question 8

What is the function of the endoplasmic reticulum? (ER)?

Answer 8

series of folded membranes that form sacs or tubes

two types- smooth and rough

Question 9

What is the difference between the rough and smooth endoplasmic reticulum?

Answer 9

rough ER:
ribosomes make it look rough or bumpy
ribosomes synthesize ( make ) proteins, so the rough ER is where this happens
smooth ER: 
smooth- no ribosomes
synthesizes (makes) lipids
detoxifies drugs

Question 10

What is the function of lysosomes?

Answer 10

made by the Golgi apparatus
full of digestive enzymes to digest unwanted particles
help white blood cells to destroy bacteria
clean-up crew

Question 11

What is the function of peroxisomes?

Answer 11

filled with enzymes to digest toxic substances
numerous in the liver
do not form at Golgi body

Question 12

what is the function of vacuoles?

Answer 12

store food, water, or waste materials

in plant cells they are very large

Question 13

What is the function of chloroplasts?

Answer 13

found in eukaryotic plant cells and some protist cells

capture light energy and convert it into chemical energy during photosynthesis

Question 14

What is the function of the mitochondria?

Answer 14

energy producers- the “powerhouse” of the cell
convert chemical energy into useable energy
found in animal and plant cells

Question 15

What is the function of the cytoskeleton?

Answer 15

overlapping network of filaments and fibers that support the cell and help it maintain its shape
can also help cells move microfilaments and microtubules

Question 16

What is the function of centrioles?

Answer 16

help to organize the cell during cell division
they migrate to either side of the cell and help to pull it apart
only found in animal cells

Question 17

What is the function of the flagellum?

Answer 17

extension of the cytoskeleton- allows movement, main source of transportation for cells
only some animals and some prokaryotes have these

Question 18

What is the function of cilia and pili?

Answer 18

extension of the cytoskeleton- allows things to move around the cell.
propels mucus in your throat, helps with hearing in your ears, and helps move food particles in your stomach
only some animal cells and some prokaryotes

Question 19

Which organelles have their own set of DNA?

Answer 19

only two organelles have their own DNA- mitochondria and chloroplasts
among multicellular animals, nearly all of the mtDNA in a fertilized egg is inherited from only the mother
one mechanism for this is simple dilution: an egg contains 100,000 to 1,000,000 mitochondria , whereas a sperm contains only 10 to 100

Question 20

What is the evolutionary origin of mitochondria and chloroplasts?

Answer 20

endosymbiotic theory
mitochondria and chloroplasts descended] from ancient prokaryotes that developed symbiotic relationships with ancient cells
in other words… mitochondria and chloroplasts are former prokaryotes that now “live” inside eukaryotes

Question 21

WHat is the fluid mosaic model?

Answer 21

the cell membrane is NOt a rigid structure with immovable components!
the cell membrane is fluid-like and flexible
within the membrane, molecules can move around

Question 22

What is the Phospholipid bilayer?

Answer 22

LIPIDS: Phospholipids made up the majority of the cell membrane
hydrophilic head made of phosphates (phospho)
hydrophobic tail made out of fatty acids (lipid)
to protect the hydrophobic tails from water,they form a bilayer which keeps the tails huddled inside and the water loving heads outside

Question 23

What is a solution?

Answer 23

molecules dissolved in a liquid= SOLUTES
Liquid/fluid dissolving them= SOLVENT
There two together make a SOLUTION

Question 24

What are concentration and equilibrium?

Answer 24

solutions will spread out their dissolved molecules until they are equal throughout
EQUILIBRIUM = molecules are spread equally
CONCENTRATION= number of molecules in an area per unit volume
HIGH CONCENTRATION: more solutes per unit volume
LOW CONCENTRATION: less solutes per unit volume

Question 25

What happens with a barrier?

Answer 25

if the solutions on either side of the barrier have the same concentration we call thatbeing at equillibrium
at equilibrium, both the solvent and solute move bak and forth acros the barrier: there is ALWAYS MOVEMENT

Question 26

transport of materials across the cell barrier

Answer 26

materials move across the plasma
membrane in two ways:
passive transport- movement cross the membrane without using energy
active transport- movement across membrane that requires energy

Question 27

Diffusion

Answer 27

solutes move across a membrane from areas of high concentration (crowded) to low concentration
because diffusion depends upon random particle movements, diffusion across cell membranes does not require the celll to use energy

Question 28

Osmosis

Answer 28

diffusion of water
water molecules (fast and small) pass through the cell's selectively permeable membrane
the solute molecule is too large to pass- only the water diffuses until equilibrium is reched

Question 29

facilitated difusion

Answer 29

large molecules or those with a charge need the help of a protein to pass across a cell membrane
proteins form a channel and molecules move through the “ doorway”
each channel is specific to a particular type of molecule
doesn’t require energy

Question 30

active transport

Answer 30

some movement across a cell membrane requires energy because it is AGainst the concentration ( it moves solutes from low to high concentration- where it’s already crowded)
when there is a difference in solution concentrations we say that there is a concentration gradient

Question 31

pump

Answer 31

a special type of protein is used to PUSH molecules to across the membrane

Question 32

endocytosis

Answer 32

a pocket (vacuole) forms around a large molecule outside the cell and buds inward to release the material inside the cell

Question 33

exocytosis

Answer 33

a vacuole inside the cell fuses with the cell membrane and forces the material outside the cell