Biology 2008-2009
Why do we need to learn about these two cell processes?
•Every cell of our body needs energy (metabolism)
•Cells only run on a certain sized battery!
•We need to consume carbohydrates to make these
batteries.
•Plants cannot consume carbohydrates.
•Plants need to make these carbohydrates first, then
turn them into batteries that will “fit” into their cells.
•Carbohydrates – contains carbon, hydrogen, and
oxygen; used for energy
•Glucose – one molecule of sugar that is needed to
make energy for the mitochondria (C6H12O6)
•Starch – a chain of glucose molecules; how plants store
their food energy
•Chloroplast – where plants make their own food (carbs)
•Mitochondria – where plants and animals turn their food
into energy
•Atom – smallest unit of matter
•Molecule – two or more atoms covalently bonded together (ex:
H2O)
•Chemical Reaction – the making or breaking of chemical bonds
•Producer – a living organism that can make its own food (plants)
•Consumer – an organism that gets its energy from eating other
organisms
•ATP (adenosine triphosphate) - molecules used by cells to drive
all reactions; battery for cell
Energy Flow in the Living World
Use your brains and/or read page 84 and answer the
following questions.
What is the ultimate source of energy for living organisms?
Sunlight
Organisms that capture energy directly from sunlight
perform the process of photosynthesis.
These organisms make their own food and are called
producers .
The organisms that consume food to get energy are called
consumers.
What happens during cellular respiration? During cellular
respiration energy that was stored in organic molecules is
used to make the ATP needed for life processes.
Chemistry Review
Why is water (H2O) considered a molecule? hydrogen and oxygen are
covalently bonded
How many atoms of hydrogen and oxygen are in one molecule of H2O?
2 H and 2 O
Determine the number of each atom in each of the following molecules.
Example: H2O = 2 atoms hydrogen, 1 atom oxygen
•6CO2
•C6H12O6
•6H2O
•6O2
Chemical Reaction – making and breaking of chemical
bonds; photosynthesis and cellular respiration are
chemical reactions.
Reactants – what goes into the reaction
Products – what comes out of the reaction
Reactants
Products
You read a chemical equation, “reactants yield
products”
Word Equation for Photosynthesis
Chemical Equation for Photosynthesis
(you will need to memorize this!)
How do plants get the reactants?
•carbon dioxide – from air, through leaves
•water – from soil, through roots
•sunlight – from sun, through leaves (green
chlorophyll within chloroplast of leaf)
What do plants do with the products?
•glucose – use to make energy
•oxygen – release into air from leaves
Photosynthesis Video
•Video Pre-Quiz
•Video Guide
•Video Post-Quiz (will be
graded for points)
Releasing Energy from Organic Molecules
Read the first paragraph on page 90 then answer the
following questions.
Organisms release energy stored as carbohydrates
(glucose) through a process called cellular respiration.
Read Figure 5-16 and answer the following questions.
True or False Only animals use the process of cellular
respiration.
True or False Plants and animals use the process of
photosynthesis.
Aerobic Respiration – making of cellular energy (ATP) using
oxygen
Word Equation for Cellular Respiration
Chemical Equation for Cellular Respiration
(you will need to memorize this!)
Where do living organisms get their reactants?
Animals
Plants
•Glucose
consumption
make it in photosynthesis
•Oxygen
inhale from air
make it in photosynthesis
What do living organisms do with their reactants?
Animals
Plants
•Water
use or perspire
use for photosynthesis or
transpire
•Carbon Dioxide
exhale
•ATP
used to power cell used to power cell
use for photosynthesis
Where within the cell is food energy
(carbohydrates) converted into energy
that the cell can use (ATP)?
Mitochondria
True or False? Plant cells and animal
cells contain mitochondria.
True or False? Plant cells use the
process of cellular respiration.
Glycolysis – first step in cellular respiration where
glucose is broken in half and a little ATP is made
Why is O2 so important?
Did you know that some living organisms can
survive without oxygen? How do they get their
energy?
Fermentation – incomplete break down of organic
compounds (glucose) in the absence of oxygen
Anaerobic Respiration – making cellular energy (ATP)
without using oxygen; same as fermentation
Watch what happens when there is no oxygen…
C6H12O6 + 6O2 → 6CO2 + 6H2O + ATP
Cellular Respiration Video