Year 11 Biology

what are prokaryotes

unicellular organisms that lack a nucleus

prokaryotes are usually around what size?

5um

DNA in a prokaryote are

circular without a protein

Ribosomes in a prokaryote are what size

70s

Prokaryotes usually have __________________

a cell wall

cell division in prokaryotes are usually undertaken by what method

binary fission

sexual recombination does not occur in a prokaryote, it

transfers DNA

the flagellum of a prokaryotic cell is the

"tail"

the pili of the prokaryotic cell is the

short hair-like substances on the outside of the cell

the nucleoid of a prokaryotic cell is the

place where DNA is held

the capsule of a prokaryotic cell is the

outermost layer of the cell

the plasmid of a prokaryotic cell is the

double stranded extra chromosomal DNA

the ribosomes of a prokaryotic cell are the

site of protein synthesis in the cell

the cytosol of a prokaryotic cell is

everything found inside the plasma membrane

a Eukaryotic cell is a cell that has a ______________ and _________________.

nucleus and other membrane-bound organelles

what does the mitochondria do?

produces ATP via cellular respiration and the transformation of Glucose via glycolysis.

What does the Rough ER do?

creates proteins via the ribosomes which are found on the outside of the Rough ER and is used to make proteins.

what does the smooth ER do?

synthesis of carbohydrates

what does the chloroplast do

produces energy through the release of oxygen and is responsible for synthesis of amino acids, nucleotides, vitamins etc.

what does the nuclear envelope do?

separates the nucleus from the cytoplasm and provides a framework for the nucleus.

What does the Golgi apparatus do?

directs proteins (rough ER) and lipids (smooth ER) produced by the ER to their final destination, transported by vesicles

what does the nucleus do

stores DNA and directs all cellular activities

what does the cell membrane do

controls what goes in and out of the cell

what does the cytosol do

allows for the diffusion of molecules throughout the cell

what does the cell wall do

provides strength to the cell and prevents osmotic stress

what is osmotic stress

when there is abnormal pressure outside the cell, leading to an imbalance in water concentrations

what does the vacuole do

stores food, water, and waste

what does the liver do to remove amino groups from a compound

it deaminates them, which forms ammonia.

what does the vesicle do

transports substances across the membrane

a Eukaryote has a larger cell size then a prokaryote with approximately _______________ in size

10-100um

a eukaryote has a ___________ and internal _________________.

nucleus, membrane bound organelles

a eukaryote has linear__________ with proteins

DNA

what is the difference between eukaryotes and prokaryotes

prokaryotes are bacteria and are unicellular, eukaryotes are plants and animals cells and are multicellular

Eukaryotes have larger ________ than prokaryotes

ribosomes

some Eukaryotes have

cell wall

cell division of a eukaryote is undertaken by ____________.

mitosis

mitosis is when

A cell reproduces itself by splitting to form two identical offspring

meiosis is when

a cell divides twice to produce four genetically different daughter cells with one-half the number of chromosomes of a body cell.

Eukaryotes have sexual recombination which is undertaken by _________

meiosis

the mitochondria produces about __________% of the chemical energy need for cellular survival

90

there are ___________ mitochondria in high requirement cell areas e.g. liver and muscles

multiple

mitochondria have a double __________.

membrane

the inner membrane of a mitochondria is ____________, and is called the _________________.

folded, cristae

the cristae has increased surface area for _______________ and _________________.

enzyme controlled reactions, faster ATP production

the cell wall is made up of ____________, which humans and animals cannot break down.

cellulose

__________ can break down cellulose

bacteria

the cell membrane is a barrier that is ________________ and only allows certain substances through

semi-permeable

the cell membrane acts to maintain a relatively stable ______________________ via the movement of substances

internal environment

the plasma membrane allows enzymatic reactions to be ________________.

localized (which helps the enzymes do their different jobs)

the plasma membrane keeps potentially harmful __________________.

reactions and substances contained

a greater membrane surface area allows the membrane to have more ____________________.

membrane-bound reactions.

greater membrane surface area can increase speed and efficiency of ________________.

metabolic reactions

the fluid mosaic mode was proposed by Singer an Nicholson in_____________.

1972

the fluid mosaic model proposed the idea that membranes are not rigid but a flexible ____________ made up of ______________.

bilayer, phospholipids

Phospholipids have a _____ head and a _____ tail.

polar (water-attracting), nonpolar (water-repelling)

the polar head of a phospholipid is water-attracting and is made up of ____________ and ______________ molecule.

phosphate, glycerol

the non-polar tail of a phospholipid is water repelling and is made up of _______________.

2 fatty acids

due to the nature of the phospholipids, they form a bilayer, where the _______________________ shield the ___________________ from water

polar heads, non-polar tails

phospholipid molecules in the membrane move and allow ___________ soluble substances to pass through

lipid

examples of lipid soluble substances include

-________________

-________________

-________________

vitamin D, Estrogen, Testosterone

cholesterol is found only in ___________ cell membranes

animal

name 4 effects of cholesterol interacting with the fatty acids in phospholipids.

-immobilize the outer surface of the membrane, reducing fluidity.

-makes the membrane less permeable to super small water soluble molecules.

-separates phospholipid tails and prevents membrane crystilisation

-helps secure peripheral proteins, which are temporary attachments to the outer surface of the cells membrane, and they help with different cellular activites.

what proteins span the outside of the membrane

extrinsic/peripheral

what proteins span the lipid bilayer of the cell membrane

intrinsic/integral.

what do proteins in the cell membrane do to support the membrane

they provide structural support

How do proteins contribute to the transport of materials around the cell membrane?

by acting as carriers to assist in the transportation

What are hydrophilic channel proteins and how do they support the rapid transport of substances across the membrane while avoiding the hydrophobic center?

Hydrophilic channel proteins are membrane proteins that span the lipid bilayer and facilitate the rapid transport of substances across the membrane by avoiding the hydrophobic center.

Do proteins in the membrane serve as receptor sites by combining with complementary shaped molecules, thus initiating reactions?

Yes, proteins in the membrane can act as receptor sites by binding with complementary shaped molecules, which then trigger specific reactions.

what are protein channels

protein channels are proteins that allow large or lipid molecules to pass through selectively permeable cell membrane through facilitated diffusion.

what are carrier proteins

specialized membrane proteins that change shape during the transport process of large polar molecules and ions.

do carrier proteins need ATP to carry out the process of transportation

There is no use for facilitated diffusion but for active transport there is a use of ATP.

what do glycoproteins and glycolipids do in a cell

act as recognition sites

there are 4 main ways of transporting small substances across the membrane:

-diffusion

-facilitated diffusion

-osmosis

-active transport

what are the three ways of passive transport

-diffusion

-osmosis

-facilitated diffusion

is energy required for passive transport

no energy is required

in passive transport particle movement is via what concentration

high concentration to low concentration to reach equilibrium

is equilibrium able to be reached generally in concentrations of molecules

not generally, especially not in living organisms.

what molecules does diffusion usually transport over the membrane

-oxygen

-carbon dioxide

-water

-fat soluble molecules

rate of diffusion depends on different factors including

-concentration gradient

-size of the molecules

-distance

-surface area

-temperature

-number of pores/channels

what is concentration gradient with regard to rate of diffusion

the greater the concentration on the other side of the membrane of molecules, the faster they move.

what is distance with regard to rate of diffusion

the shorter the distance needed to travel to the diffusion, the faster the molecules move.

what is size of molecules with regard to rate of diffusion

the smaller the molecule, the faster it diffuses.

what is surface area with regard to rate of diffusion

the larger surface area, the faster the diffusion

what is temperature with regard to rate of diffusion

the higher the temperature the faster the diffusion.

how does the number of pores/channels in the membrane affect rate of diffusion

the higher the numbers of pores/channels that molecules are able to pass through the membrane, the faster the diffusion.

what is osmosis

diffusion of water over the cell membrane

what are aquaporins

Channel proteins which facilitate water diffusion through the membrane by forming hydrophilic channels.

water in the cell moves from what concentration

high to low concentration.

How does the concentration of the surrounding solution influence the state of a cell?

if the concentration of substrate is higher outside the cell, the substrate will move out of the cell. If the concentration of substrate is lower inside the cell, the substrate will move into the cell.

there are 3 possible concentrations that affect the state of the cell

-isotonic

-hypotonic

-hypertonic

what is isotonic with regards to concentration of water outside the cell

no net movement of water due to concentrations inside and outside the cell are equal.

what is hypotonic with regards to concentration of water outside the cell

high concentration of water outside the cell, so water moves inside the cell

what is hypertonic with regards to concentration of water outside the cell

there is a higher concentration of water inside the cell, so water moves out of the cell.

what proteins does facilitated diffusion use

carrier and channel proteins

Which molecules and atoms require facilitated diffusion through the cell membrane due to their size and charge limitations?

large molecules and charged atoms.

what do channel proteins do to the membrane

produce pores in the membranes so charged particles can move through

what do carrier proteins do to allow larger molecules in or out of the cell via facilitated diffusion

they change their shape

does facilitated diffusion use energy

no energy

how does facilitated diffusion transport molecules with regard to the concentration of the molecules

high concentration to low concentration.

which increases faster with regards to cells - volume or surface area

volume