12 BIO - cells

what is a prokaryote?

a prokaryote is a unicellular organism that does not have nuclear bound dna or nuclear bound organelles.

what is a eukaryote

a unicellular or multicellular organism that has nuclear bound DNA and has mebrane bound organelles, is larger and more complex than prokaryotes.

what is a plasma membrane?

is the outer most layer of a cell. it is made almost entirely or proteins and lipids with a small amount of carbohydrates. its function is to protect the cell and organelle contents, allow a concentration gradient to occur, and has selective permeability allowing only some substances in. it is very thing so makes transport fast

what is the phosphlipid bilayer

double layer of phospholipids with hydrophilic heads facing outwards and hydrophobic tails facing inwards. its function is to form the main structure of the membrane and acts as a semi permeable barrier. passive transport through simple diffusion of small or non polar molecules

what are protein channels

tube like proteins that span across the membrane and allow specific ions or small polar molecules to move through the membrane. passive transport (facilitated diffusion)

what are carrier proteins

proteins that bind to molecules and change shape to move them across the membrane. transports specific substances such as glucose across the membrane. passive transport (facilitated diffusion)

what are protein pumps

proteins that use ATP energy to move substances across the membrane. moves substances against the concentration gradient (active transport)

what are glycoproteins

proteins with attached carbohydrate chains on the outer surface involved with cell recognition, communication, and receptor binding, not direclty involved in transport.

what is a glycolipid

lipids with attached carbohydrate chains. help with membrane stability and cell recognition not directly involved in transport.

what is cholesterol

lipid molecules imbedded between phospholipids. maintains membrane fluidity and stability. not directly involved in transport.

what are lipids

serve as essential long term energy storage, form the structural base of cell membrane

what is the definiton of passive transport

passive transport is the movement of molecules from a high concentration to a low concentration (move along with the gradient) it does not require ATP however sometimes requires membrane protein.

what is the definition of active transport

active transport is the movement of molecules across from a low concentration to a high concentration will require a membrane protein and ATP

what is osmosis

osmosis is the net movement of water molecules from a region of high water potential (lower solute concentration) to an region of low water potential (high solute concentration) across a selectively permeable membrane. moves with the concentration gradient and does not require ATP.

what is diffusion

diffusion is the passive net movement of particles from an area of higher concentration to an area of lower concentration down a concentration gradient there are three types of diffusion simple, facilitated, and osmosis.

what is a semipermiable membrane

a barrier that allows some molecules or ions to pass through whilst blocking others.

what is a hypertonic solution

when the concentration of solute is higher outside of the cell than inside. water will move out of the cell causing the cell mass to decrease. water exits the cell to equalise the solute concentration on both sides of the membrane.

what is a hypotonic solution

the concentration of solute is higher inside the cell than it is outside, water will move into the cell causing it to gain mass (resulting in cells swelling or bursting) water moves to to equalise solute concentration on both sides of the membrane.

what is a isotonic solution

when the solute concentration is at equilibrium, equal inside and outside of the cell. there is not net water movement and the cell mass remains at a constant.

what does plasmolysed mean

when the vacuole is dehydrated from water moving out of the cell that it shrinks causing the protoplasm (cytoplasm and membrane) to shrink and detach from the rigid cell well

what is photosynthesis

the process by which plants use carbon dioxide and water in the presence of chlorophyll and sunlight to produce glucose and oxygen, it occurs in the chloroplast.

what is the equation for photosynthesis

carbon dioxide + water → glucose + oxygen OR 6CO₂ + 6H₂O → C₆H₁₂O₆ +6O₂

what is a thylakoid

a membrane bound compartment inside a plant chloroplast where the light dependant reactions of photosynthesis occur.

what is the stroma

a colourless fluid like gel that fills the inner space of a chloroplast and surround the thylakoid stacks.

what is the granum

a stacked coin shaped structure of thylakoid membranes inside the plant chloroplast

what happens during a light dependant reaction (LDR)

the light dependant reaction occurs in the thylakoid membrane it uses photons (energy from the sun) to break down water in to H⁺ ions and O₂ is released

what is the equation for LDR

2H₂O → 4H⁺ + O₂ 4H+ gets picked up by NADP+ to become NADPH and O2 is a waste product so it diffuses out

what happens in a light independant reaction (LIR)

what is the equation for LIR

what is respiration

respiration is the controlled release of energy from glucose to form ATP which is usable energy for cells

what is anaerobic respiration

anaerobic respiration is a cellular process that breaks down glucose without oxygen to release smaller amounts of energy much quicker. produces lactic acid which causes cramps in muscles and is toxic to cells (builds up) occurs in the cytoplasm, can occur in both yeast/ bacteria and in animals

what is aerobic respiration

aerobic respiration is a cellular process that breaks down glucose using oxygen to release large amounts of energy. occurs primarily in the mitochondria. has 3 main enzyme controlled reactions glycolysis (first stage of aerobic and anaerobic respiration generates 2ATP per glucose molecule- only reaction for anaerobic) krebbs cycle (second stage of aerobic respiration generates 2 ATP) and electron transport chain (occurs in the inner mitochondria membrane is the third stage of aerobic respiration and produces 34 ATP)

what is the equation for aerobic respiration

C₆ H₁₂ O₆ + 6O₂ → 6CO₂ +6H₂ O +38ATP + heat (GO COWA) glucose + oxygen → carbon dioxide + water + atp (heat)

what is the equation for anaerobic respiration

(GALA) glucose → lactic acid + 2ATP (C₆ H₁₂ O₂ → 2C₃ H₆ O₃ +2ATP)

what is the function of the mitochondria

to carry out aerobic cellular respiration to produce usable chemical energy for the cell in the form of ATP

what are the factors that affect the rate of respiration

glucose availability, oxygen availability, temperature (temp below optimum rate of respiration will decrease as enzymes will slow. above optimum temp rate of respiration will decrease cause the enzyme denature.) , cell body energy demand (muscle cells, heart cells, brain cells)

what are enzymes

are globular proteins folded into complex, specific shape that allows only a certain molecule to fit into them. they function as biological catalysts that speed up the rate of reaction without being used up in the process

what is activation energy

the energy needed to break bonds and start a reaction (the minimum amount of energy an atom must posses in order to react)

what are the factors affecting enzymes

PH, enzyme concentration, substrate concentration, temp, cofactors, inhibitors.

what is DNA

Dna is a polymer made up of many repeating monomer units called nucleotides it acts as the long term storage and transmission for genetic codes.

what is DNA replication

DNA replication is semiconservative (have the new DNA strand is new the other is old) and produces 2 identical copies of DNA so that cells have the correct genetic information and the correct function

what does helicase do

helices separates the parental strand by breaking the hydrogen bonds between nitrogenous bases

what does ligase do

ligase joins DNA fragments together by fusing the okazaki fragments back together creating a continuous strand

what does DNA polymerase do

DNA polymerase builds the new DNA strand by adding matching nucleotides and reading 3 prime to 5 prime

what does primase do

primase adds primers along the parental strand allowing DNA polymerase to know where to start synthesising

what is a leading and lagging strand

the leading strand is a new DNA strand that is built continuously in the same direction as the unzipping. the lagging strand is built discontinuously in short pieces (Okazaki fragments)

what are okazaki fragments

fragments of shortly new made peices of DNA found on the laggin strand

what is the cycle of a cell

interphase (G1, G2, S) and mitotic phase

what happens in the interphase

during interphase the cell grows and depilates its DNA and prepares for division

what happens in the mitotic phase

a cell divides its previously copied DNA and cytoplasm to create two genetically identical daughter cells.

what happens in cytokinesis

the cytoplasmt of a single cell divides to form two identical daughter cells

what is mitosis

a single cell divides to produce two genetically. identical daughter cells with the same genetic material this is used for the growth and repair of cells.

what happens in G1

a newly formed cell physically grows larger duplicates it organelles and performs normal metabolic activities while preparing to copy its DNA

what happens in G2

the cell does its final preparation before cell division it grows larger makes extra proteins and cell parts saves up energy and checks the copied DNA for any mistakes

what happens in S

the cell copies all nuclear DNA in it chromosomes this doubles the amount of genetic and creates two identical sister chromatids for every chromosomes so the cell can divide later.

what does NADP+ do

NADP acts as an electron carrier that accepts high energy electrons and a hydrogen ions to become NADPH during photosynthesis

what does NADPH do

in plants, it captures energy during the light dependant reactions and delivers electrons to to the calvin cycle to help turn carbon dioxide into glucose.

what is simple diffusion

the movement of particles from an area of high concentration to an area of low concentration without using cell energy. (gases O2 and CO2) direct crossing without any proteins or carriers stright through the cells lipid bilayer

what is facilitated diffusion

the passive movement of molecules or ions across a cell membrane through specialised transport proteins moving from an area of high concentration to an area of low concentration (involves channel proteins and carrier proteins) moves large polar molecules, ions, and amino acids

what does a cofactor do for ROR

a co factor is a non protein chemical compound that is required for the enzyme to function properly. cofactors generally sit in the enzymes active site and assit the binding of a substrate.

what does PH do for ROR

changes in PH can disrupt the weak intermolecular forces that hold an enzyme together causing it to denature (lose its shape) as a result the substrate wont fit into the active site. once an enzyme denatures it will not function again.

what does temp do for ROR

increasing temp increases the frequency of collisions and the formation of enzymes- substrate complex and therefore the rate of reaction if the temp gets too high the enzymes will denature and the substrate can no longer bind

what does enzyme concentration do for ROR

increasing enzyme concentration increases the frequency of enzyme substrate collisions and the rate of reaction but eventually there are more enzyme than substrate. some enzymes become redundant and there is no further increase in ROR

how does substrate concentration impact ROR

increasing substrate concentration increases the frequency of reactions rate and enzyme substrate complex collisions but eventrually all the enzyme active sites are already occupied (saturated) and there is not furtthur increase in ROR

how do inhibitors affect ROR

competitive inhibitors bind to the active site and prevent substrate from binding ( this inhibitor can be over come by adding excess substrate) non competitive inhibitors bind to a regulatory region which alters the shape of the active site.