2BIO ALL KEYWORDS

Cell membrane

Double layer of lipids enclosing the cytoplasm

acts as a protective barrier to transport substances in and out the cell

formula for ANAEROBIC respiration

C6H12O6 -> 2C3H6O3

formula for AEROBIC respiration

C6H12O6+6O2→6CO2+6H2O+ATP

formula for photosynthesis

6CO2+6H2O+Light Energy→C6H12O6+6O2

Cell wall

Cellulose layer that surrounds plant cells

provide structural support, maintain shape

Cells

the basic building blocks of living things

chloroplast

organelle which is the site of photosynthesis

cillia

hair-like projections used by the cell to move

cytoplasm

semi-fluid substance filling the cell interior

a jelly-like fluid that holds organelles in place and provide a place where chemical reaction can happen

cytoskeleton

structure which maintains the shape of the cell

endoplasmic reticulum

system of membranes and connecting tubes

purpose is to synthesize proteins (RER) and steroids (SER) and to transport them

flagellum

A whip-like extension which enables locomotion (movement of organism)

Golgi Body

Flat disc-shaped sacs in the cytoplasm

purpose is to transport, sorting and modification of both protein and lipid

lysosome

sac containing digestive enzymes

breaks down dead or worn out organelles

Mitochondria

organelle where aerobic respiration happens

generates most of the cells energy in form of ATP through cellular respiration

nucleus

structure in cell containing genetic information as DNA in chromosomes

organelles

various structures within the cytoplasm

Ribosomes

site where protein synthesis happens

vacuole

sac containing water or storage products

Active transport

using energy to move molecules against a concentration gradient

concentration gradient

difference in concentration either side of a semi-permeable membrane

diffusion

moving from high to low concentration

endocytosis

taking large molecules into a cell by moving the cell membrane to form vesicles

facilitated diffusion

A passive transport method that uses one type of molecule to move another

flaccid

a cell that has lost its shape due to a loss of turgor pressure

ion pump

a protein channel in the cell membrane that moves ions against the concentration gradient

osmoregulation

the control of osmotic pressure inside cells

Osmosis

the movement of water from an area of high to low water potential

passive transport

any method that moves a substance down a concentration gradient without using energy

phagocytosis

type of active transport that “eats” large particles such as bacteria. located in white blood cells.

pinocytosis

taking water into the cell by cytosis (cell drinking

semi-permeable

A membrane that will let through very small molecules but not larger ones (controls which substances can pass through while others cant)

surface area:volume ratio

a measure of how much surface area there is per unit volume.

If SA and V increase the SA:V ratio decreases

If SA and V decreases the SA:V increases

turgor

osmotic pressure inside a cell that helps it keep its shape

vesicle

used for transporting substances to or from the cell membrane

activation energy

amount of energy needed to start a reaction

active site

part of enzyme which substrate fits into

aerobic respiration

releasing energy from food using oxygen

anaerobic respiration

occurs in the absence of oxygen

ATP

carries small amounts of energy for the cells to use for processes

catalyst

reduces the activation energy for a reaction

cofactor (non protein) AND coenzyme (organic)

a chemical that acts WITH an enzyme; completes the active site

electron transport chain

reactions on cristae of mitochondria; generates most ATP; H2O = waste

enzyme

biological catalyst with an active site specific to the substrate(s)

fermentation

results in alcohol and carbon dioxide gas

glycolysis

splits glucose into two pyruvate molecules

kreb's cycle

series of enzyme catalysed reactions in the mitochondrial matrix CO2 = waste

light dependent phase

uses sunlight to split water into hydrogen and oxygen; also charges up ATP

light-independent phase

fixes carbon as glucose

substrate

chemical that an enzyme acts upon

membrane bound organelles

regular organelles found in the cytoplasm

prokaryotic cells

no membrane bound organelles

eukaryotic cells

have membrane bound organelles

DNA replication

to create two identical copies of the DNA, making sure that during cell division each daughter cell has a set of genetic instruction

Double helix

DNA consists of two long strands which are twisted around each other forming a helix. The strand runs from opposite directions (5' to 3’) and (3’ to 5’)

DNA polymerase

synthesizes new strands by adding nucleotides

Helicase

The enzyme responsible for unwinding the DNA during cell division by breaking hydrogen bonds

Primase

synthesizes a short RNA primer since DNA polymerase needs this primer for DNA synthesis

DNA synthesis

AKA DNA replication where two copies of the DNA are produced

RNA primer

a short segment of RNA nucleotides that acts as a starting point in DNA synthesis

DNA ligase

joins the okazaki fragments which creates a continuous strand

Leading strand

synthesized continuously TOWARDS the replication fork

lagging strand

made up of short fragments (okazaki fragments) AWAY from the replication fork

replication fork

location where ezymes do their jobs like

helicase : unwinding the strands

synthesized

build or made

okazaki fragments

short fragments of DNA synthesized on the lagging strand during DNA replication

synthesized mean by how DNA polymerase copies that specific strand during replication

adaptation

feature that helps the organism survive and reproduce in their environment

allele

One of the alternative forms of a gene - due to mutation (allele is a trait)

allele frequency

how much a specific allele occurs in the population compared to the other alleles in that gene

autosome

Any of the chromosomes in a cell other than sex chromosomes

bottleneck effect

Population decreases due to a natural disaster leaving only a small number of individuals in that population

centromere

Part of the chromosome that attaches to the spindle during cell division

chiasma

A point on a chromosome at which crossing over can occur

chromatid

One of the two identical copies formed after DNA replication

chromosome

A chromosome is a long, thread-like structure made of DNA that carries genetic information

codominance

Inheritance pattern where both dominant alleles are fully expressed TOGETHER in the phenotype

crossing over

An exchange of pieces of chromatids between homologous chromosomes

dihybrid

A genetic cross between parents that differ in two characteristics, controlled by genes at different loci

diploid

Diploid has two sets of chromosomes, one from each parent 3 double strand chromosome (one set is 3 chromosomes)

Haploid

Haploid has one set of chromosomes (just 3 single strand chromosomes)

directional selection

extreme trait is favoured so the populations characteristics shifts to that trait.

Extreme trait is the very far range possible for example short, medium, long, long is the extreme trait.

disruptive selection

Extreme trait has advantages while medium trait has disadvantages

DNA

A nucleic acid that is the genetic material of most living organisms - a major component of chromosomes

dominant

Allele that is always expressed when present

evolution

the process where the population gradually change over time where certain traits become more common due to improving survival and reproduction

founder effect

small amount of the population leave their current environment to establish a new community taking only a small amount of alleles with them therefore the alleles that were once commonly expressed now have a less chance to be expressed (recessive)

gametic mutation

Change in DNA that occurs in gametes (sex cells e.g sperm, eggs)

gene

A segment of DNA that codes for specific trait or protein

gene flow

Alleles moving from a population to another may be due to migration or interbreeding

gene pool

The sum total of alleles present in a population

genetic drift

Random changes in allele frequency - effect greater in small populations

genetic equilibrium

Describes when the frequency of an allele in a gene pool does not change from generation to generation

genotype

Allele combination possessed by an organism for a trait

germline

The series of cells that eventually produces gametes

heterozygous

Genotype with two different alleles for a trait (e.g RW)

homologous

Chromosomes that are the same size and shape

homozygous

Genotype with two identical alleles (e.g RR)

immigration

The movement of individuals into a population

incomplete dominance

neither allele is dominant therefore there is a mix of alleles in the zygote (RW) (RW itself is a zygote)