Cell wall on outside of
membrane to protect and give
the cell its shape
Have Chloroplasts present
containing green chlorophyll
pigment that absorbs light
energy (site of
photosynthesis)
contain large vacuoles
(storage)
Major organelles
structure and
functions
Nucleus
control centre of the cell
containing genetic
material (DNA)
Nucleolous
(located in the
nucleus)
site for production of RNA
"messenger chemical that
holds the instructions for
the organelles. surrounded
by a nuclear membrane
with pores allowing RNA
through
Mitochondria
site of cellular
respiration "power
stations"
converting energy
from food
(photosynthesis)
into readily usable
for of ATP (energy
molecule) -
contains folded
membranes
increasing SA
Endoplasmic Reticulum
smooth
Rough
covered in RIBOSOMES
Site of protein production
both: network of
membranes
forming channels
and
compartments in
the cytoplasm
Golgi Apparatus
in charge of
packaging
chemicals into
membrane sacks
for either storage
or secretion from
the cell
Lysosomes
destroy/break
down any foreign
bodies in cell and
rapidly digest
dead contents
(waste desposal)
Cell theory
All
living
things
are
made
up of
cells
all cells come
from pre-existing
cells
types of microscopes
Light
Electron
History of our knowledge of cells
Virchow and
Flemming clarified
cell division --> all
cells come from
pre-existing cells
Robert Hooke observed a piece
of cork and noted "cell" type
compartments
Robert Brown
discovered
structures
"organelles" in
cells, noted the
nucleus
chemicals move in
and out through
membranes
Cell Chemicals
Identifying tests
Glucose: tested by
Benedict's solution
(yellow or orange)
Starch: tested by Iodine
Solution (dark blue or
black)
Protein: tested by
Biuret (Purple)
Structure of Cell Membranes
Two layers of phospholipids.
molecules cling to each other in a
line up with hydrophilic ends on
outside, attracted to water
solution in cytoplasm.
Hydrophobic ends repelled, cling
together inside the membrane.
Other molecule in phospholipid
bi-layer; proteins, carbohydrates
serving purposes of receptors for
messenger chemicals,
identification markers identifying
own cells from foreign invaders
and helping chemicals through
the membrane.
Passive transport
(uses no energy ATP)
diffusion
movement of
molecules/ions
from an area of
high concentration
to an area of low
through
Osmosis
Diffusion of water
through a
semi-permiable
membrane from an
area of low
concentration to an
area of low
SA: VOL ratio
Nutrition in plants and animals
Photosynthesis
water + carbon dioxide --> glucose + oxygen
occurs in chlorophyll
in leave of plants,
capturing energy from
light and stores it in
high energy food
compound --> glucose
Cellular Respiration
Glucose + oxygen --> carbon dioxide + water
Releases stored energy in for of ATP -->
powers all cellular and life activities
Structure and functions of a leaf
Factory for photosynthesis
Waxy cuticle layer: allows light through +
water proof preventing excess water loss
upper epidermis layer: transparent letting in light
Palisade layer: tightly packed under
epidermis layer absorbing maximum
light containing chloroplasts "engine
room" for photosynthesis
Spongy layer: loosely packed cells
--> allows for gas exchange via
diffusion
Lower epidermal layer: many openings (stomates)
allowing water to evaporate throught process of
TRANSPIRATION and carbon dioxide diffuses into
leaf and oxygen out
Stomata (stomates)
opening formed between
special "guard cells" that
close to minimise water
loss in dry periods and
open when right condtions
Digestion in Animals
Comparisons in
structures compared to
diet
Carnivore: Sharp
teeth, tear at food
and swallow in
chunks --> relatively
short intestinal tract,
elastic stomach to
hold large amounts
of food
Herbivore: flat grinding teeth,
long intestinal tract (longer
time for digestion), Bacteria
living in gut have enzymes to
digest cellulose
Nectar Eaters: Simple
digestive tract (sugars are
simple to digest)
Gas exchange and
internal transport
Gas exchange in animals
frogs:simpler than
mammals, dont have
alveoli. Gas exchange
also happens through
their skin, mouth and
throat cavities --> are
kept moist and lined with
blood vessels.
Mammals: (humans)
lungs contain alveoli
to increase surface
area, inside of lungs
also moist allowing
gases to dissolve
and diffuse
insects: dont have
lungs, has holes called
spiracles allowing air to
move through network
of tubes (trachea)
infiltrating the body.
Efficient in small
animals, not in larger
ones
Fish: gas exchange
occurs through feather like
plates consisting of
thousands of tiny filaments
each filled with blood
capillaries in which water
flows over taking in
oxygen. Blood flow in gills
is opposite than flow of
water making exchange
more efficient.
Circulatory systems
in animals
open system
(insects)
Simpler circulatory
system where the blood
doesnt always stay inside
a blood vessel and the
blood isnt forced to flow
constantly
Closed (vertebrates)
Blood is always flowing
inside a blood vessel,
pumped around by the
heart. highly efficient
keeping the blood
flowing. guaranteeing a
steady flow of nutrients,
gasses and wastes
between body cells and
the outside environment
Gas exchange and
transport in plants
Phloem tissue
(active transport)
tubes transporting
sugars and nutrients
from the leaves
through out the plant
to other
un-photosynthesising
parts
Xylem Tissue
(passive transport)
Carry water and
dissolved minerals
from roots to leaves
in an upward
movement
Cell division for growth and repair
process of mitosis
Parent cell makes a copy of
its genetic information
chromosomes group together and
line up in middle of the cell before
separating into to identical groups
set of chromosomes forms
new nucleus
Cell membrane grows and divides
cell into two parts with a sharing of
cytoplasm and organelles in each