Keywords: Diffusion, Chloroplast, Vacuole, Cell wall, Nucleus, Mitochondria, Homozygous
Factors affecting
diffusion
Respiration (in mitochondria)
Aerobic (all the time)
Temperature
Used in lungs; O2 diffuses into the
blood and CO2 diffuses into lungs
Mitochondria
Concentration
gradient
Glucose + O2 → H2O + CO2 (+
energy)
Glucose → Lactic acid (+
energy)
Diffusion distance
Energy used for: heat,
movement, build large
molecules
Incomplete breakdown of
glucose (less energy released)
Surface area : Volume
Palisade cell
Sperm cell
Ribosomes
Cytoplasm
Chloroplast
Many
mitochondria
Streamlined
Vacuole
Nucleus
What is the
function of each
organelle?
Tissues
Organs
Stored as starch
Photosynthesis
Plant Nutrients
Glucose + Oxygen
Light and chlorophyll are
also needed
In the LEAVES of
plants! Lots of
chloroplasts for
photosynthesis.
Cells
Cell Membrane
Cell Wall
Carbon dioxide + Water
Anaerobic (when exercising)
Nitrates-to make proteins
Magnesium-to make chlorophyll
Organ
systems
Root hair cell
3 Limiting factors -light
-temperature
-CO2
At first as CO2
increases so does photosynthesis
but only up to a certain point.
Here light or temperature is the
limiting factor.
Population
isolated due to…
Speciation
In the ROOTS of
plants!
Large surface area
for uptake of
water & minerals
Animal
tissues
Plant
tissues
Muscle
Epidermis
Glandular
Mesophyll
Epithelial
Phloem/
xylem
Potassium-aids respiration
Phosphorous-aids respiration
Oxygen debt (need oxygen to
get rid of lactic acid)
Isolation
New population
exhibit variation
Genetic Variation
Natural Selection
Speciation
Leaves
Waxy cuticle-keeps water in
Epidermis - Protection
Palisade mesophyll layercells contain lots of
chloroplasts to capture
light
Stomata on lower surface
to allow gases in/out
Some individuals
more likely to
survive and
reproduce
New population
no longer able to
interbreed with
old population
Causes of extinction
Disease
Hunting / predators
Loss of food / prey
Loss of habitat /
natural disaster
Climate change
Spongy mesophyll layer has
air spaces to allow gases to
move between cells
Keywords: Allele, Dominant, Recessive, Mitosis, Meiosis, Enzyme, Substrate, Active Site, Denatured, pH, Concentration gradient
1)
2)
3)
Enzymes –biological catalysts that
speed up reactions yet remain
unchanged e.g. respiration in
the mitochondria
1) Enzyme and substrate
2)Substrate binds to active site
3) Substrate is broken down
A cell nucleus contains
46 Chromosomes, which
carry genes. Different
versions of genes are
called alleles.
A chromosome is a DNA
double helix
Enzymes have an optimum
temperature and pH. Changes in
pH/temp can denature the
enzyme so its shape changes and
the substrate can’t bind to the
active site
Uses of Enzymes
-Biological washing powders
-In baby foods (proteases)
-In slimming foods- fructose is
made using isomerases.
Fructose is sweeter than
glucose so less is needed.
Enzymes and digestion
Large molecules are broken down so they
can be absorbed.
-Amylase breaks down starch into sugars in
the mouth and small intestine.
-Proteases breakdown proteins into amino
acids in the stomach and small intestine.
-Lipases breakdown fats into fatty acids and
glycerol in the small intestine.
- Enzymes in the stomach work best at acidic
pH’s; enzymes in the small intestine work
best at alkaline pH’s (bile neutralises acid
from the stomach and provides these
conditions).
Starch
46=chromosomes in normal cell
23=chromosomes in sex cells
glucose
Stem cells: unspecialised;
differentiate to form other cells
(used for repair); from bone marrow
or embryos
A gene
codes for
specific
sequence of
amino acids,
to make a
specific
protein
Caused by recessive allele (so
two copies of allele are
needed).
A thick sticky mucus is
produced affecting air
passages and digestive systems
Polydactyly-Caused by dominant
allele (so only one of allele are
needed). Affects the number of
digits.
Treat illness
Expensive
Ethics of
using embryo
Early organisms = softbodied = few fossils
Fossilisation = rapid
burial, no oxygen,
replacement of tissues,
time, discovery…
Parents
Cc
x
Cc
Gametes
C or c
x
C or c
(egg/sperm)
Possible Outcomes
C
CC
Cc
c
Cc
cc
Mitosis-used for
normal cell
growth
1) Parent cell
2) Chromosomes make
identical copies
of themselves
3) One cell division
occurs
4)Two daughter cells
form each with
46 identical
chromosomes to
the parent cell
Physical factors
affecting
distribution of
organsism:
Temperature,
Nutrients, Light,
Water, CO2/O2
Proteins
Made of amino acids
Examples = enzymes,
hormones, antibodies
c
C
25% sufferers
Cystic Fibrosis
Cons
FOSSILS!
Inheritance- Parents who are both carriers of
the Cystic fibrosis allele (c).
75% Normal
Pros
Meiosis –used to
make the sex
cells (gametes)
-the chromosomes
are copied
-two cell divisions
to give four cells
- Cells contain
half original
chromosome
number