There are 3 ways things move in
and out of a cell.
1. Diffusion (Passive Transport)
2. Osmosis (Passive Transport)
3. Active Transport
Diffusion
Movement of molecules from high
concentration to low concentration.
Osmosis
The diffusion of just water molecules
through membranes.
A simple rule to remember is:
the water from one side of a
membrane to another
http://animation
Active Transport
The movement of molecules through the
membrane using energy.
Photosynthesis and Respiration
► Photosynthesis
► Respiration
► Fermentation
Fun Facts
► The
first cells on the earth are thought to have
been capable of neither photosynthesis nor
respiration.
► However, photosynthesis must have preceded
respiration on the earth, since there is strong
evidence that billions of years of photosynthesis
were required before O2 had been released in
sufficient quantity to create an atmosphere rich in
this gas. (The earth's atmosphere presently
contains 20% O2.)
Forests are sometimes called Earth’s
lungs because they produce much of the
oxygen we breathe…but they produce
only 50% of the oxygen!
Kelp, coral with photosynthetic
algae, and diatoms (algae) help
create the other 50% of the
oxygen.
Photosynthesis
► Photosynthesis
is the process by which plants,
and some bacteria, use the energy from
sunlight to produce sugar.
Photosynthesis
IN: Sunlight
Water
CO2
OUT: O2
ATP (glucose)
How does the plant get:
1.
2.
3.
Water
CO2
Sunlight
Water
► Plants
suck up water
through their Xylem
and let the water flow
out in a Phloem.
CO2
► Plants
let O2 and CO2 in and out through little
openings under their leaves called stoma.
Pea Leaf Stoma
Sunlight
The process of photosynthesis takes place in the
chloroplasts, specifically using chlorophyll,
the green pigment involved in photosynthesis.
Why Green?
► Chlorophyll,
the green pigment in Chloroplasts,
absorbs all wavelengths of light except green,
which is reflected to our eyes.
Why do leaves lose the green?
► As
the chlorophyll in leaves decays in the
autumn, the green color fades and is
replaced by the oranges and reds of
carotenoids (other pigments covered by the
green chlorophyll)
Question: What does the plant do to break the
glucose into energy?
Answer: RESPIRATE (yes, just like you and me)
Fact: We need plants to produce O2 for us to
breathe.
Question: Do plants need us to produce CO2
for them?
ANSWER: NO. Plants use CO2 to create
Carbohydrate and O2 to break the
carbohydrates into energy.
Respiration
So what is respiration?
During respiration, glucose reacts with oxygen to produce energy.
Energy is needed for growth, repair and movement.
Water and carbon dioxide are bi-products of respiration - they need to be excreted.
ALL LIVING ORGANISMS (even plants!) NEED TO RESPIRATE!
Lingo…
Respiration is the release of energy from
glucose or another organic chemical.
Aerobic Respiration requires oxygen.
Anaerobic Respiration does not require
oxygen and releases less energy.
(Breathing: act of pulling air in/out)
Where in the cell does respiration
occur?
In plants: the mitochondria
In animals: the mitochondria
Mitochondria
Mitochondria are very important
organelles - it is in the
mitochondria that respiration
occurs. There are thousands of
them in every cell in your body.
When Glucose enters the cell,
it is broken down into smaller
molecules. (AKA: Glycolysis)
Those smaller molecules are
taken in by the mitochondria,
and with O2, are turned into
ATP (energy) (AKA:
Respiration)
Types of Respiration
► Aerobic
Respiration
► Anaerobic Respiration
 Lactic Acid Fermentation
 Alcoholic Fermentation
Aerobic Respiration
► The
use of O2 to break the glucose into ATP
(energy)
► Lots of Energy is released by this process.
Glucose + Oxygen = Carbon Dioxide + Water + Energy
Anaerobic Respiration
► Also
known as Fermentation
► Anaerobic Respiration is the release of energy
from glucose in the absence of oxygen.
► It only produces a little bit of energy (only 2 ATPs)
► It occurs where there is little O2 (single-cell
organisms in ponds) or when there is not enough
O2 in the cells.
► Two Types of Fermentation:
 Lactic Acid Fermentation
 Alcoholic Fermentation
Lactic Acid Fermentation
► The
side effects of Lactic Acid Fermentation is
Muscle Fatigue, Pain, Cramps, and you feel
Soreness.
► Fermentation is a series of enzymatic reactions
where glucose is incompletely metabolized into
lactate.
Alcoholic Fermentation
► Occurs
in yeast and some single-celled
organisms.
Sugar
====>
Alcohol
(Glucose)
(Ethyl alcohol)
Bread
+ Carbon dioxide gas
Cheese
Root beer
Getting the O2 in and CO2 out
All vertebrate animals that live on land have lungs. When we
breathe in, the muscle below the rib cage (called the diaphragm) is
pulled down, and air gets sucked into the rib cage, filling the lungs.
Blood cells circulating through tiny blood vessels near the lungs pick up
oxygen and carry it around the body to the sites of respiration. Air is
then forced out of the lungs as the diaphragm bows upwards.
Birds are different from humans in many ways. As you probably know,
they fly, and their bodies are well adapted for flight. Their lungs are very
efficient: they take in much more oxygen per breath than other animals
do. Because they get this extra oxygen they have lots of energy to
direct to the flight muscles in their wings - they can flap away for hours!
Frogs and toads have lungs, but when they
are in water they can also breathe through their
skin.
► What
animal does not have lungs? How do
they breathe?
Most fish use gills to breathe. Gills are structures that allow water to pass
through very fine channels. Next to these channels are blood vessels, with
very thin walls that let the oxygen move from the water into the blood.
If there's oxygen in the water, then why can't
humans breathe water?
►
Because oxygen has to move from the water into our blood, which is
much slower than when oxygen moves from the air into our blood.
Gills are specialized to handle this slow movement, but our lungs can't
pick up oxygen from the water fast enough to keep us alive, which is
why we drown if we try to breathe water.
Movement of O2
Review
►NOVA