Endothermic and Exothermic
Chemical Reactions
 Exothermic:
 Chemical reactions that release energy in the form of
heat, light, or sound.
 Ice pack releases cold
 Endothermic:
 Must absorb energy to function.
 Cannot occur spontaneously.
 Leg absorbs cold.
http://explore.ecb.org/videos/VLC_file?TYP
E=Image&P1=2598&REFERER=OTHER
http://chemistry.about.com/cs/generalchemistry/a/aa051903a.htm
Kinetic and Potential Energy
• Kinetic energy is greatest during
movement
• Potential energy is greatest before
movement
http://www.greenscreen.org/articles_sr/Energ
yPotentialAndKinetic.htm
Exothermic Vs.
Endothermic Chemical
Reactions
Exothermic - Releases energy in
the form of light or heat
Endothermic - Absorbs energy
from surroundings in the form of
heat.
Kinetic Vs. Potential
Energy
Kinetic - Gained energy by
acceleration or motion.
Potential - Amount of energy
based on position.
(Energy is never destroyed but it
is restored - Law Conservation of
Energy)
Cell Respiration
Reactants:
6O2+C6H12O6
Glucose+ Oxygen
+Water+ Energy
Products:
6CO2+6H2O+Energy
Carbon Dioxide
Purpose of Celluar Respiration
The process that releases energy by breaking down glucose in
the presence of oxygen.
• celluar respiration puts the carbon dioxide back into the
atmosphere (which was removed from photosynthesis)
• Takes place in mainly eukaryotes
• and some prokaryotes.
•Ailson :’)
•http://staff.jccc.net/pdecell/cellresp/respintro.html
Cellular respiration
 Purpose - to break down glucose and other food
molecules in order to get energy. This requires the
presence of oxygen.
 All cells perform Cellular Respiration. Eukaryotic
cells perform respiration in the Mitochondria.
Cellular respiration
6O2+C6H12O6----->6CO2+6H2O+energy
(oxygen + glucose ---> carbon dioxide + water + energy)
•Reactants - C6H12O6 & O2 (glucose and oxygen)
•Products - CO2 & H2O (oxygen and water)
Aerobic and Anaerobic Respiration
Aerobic
Anaerobic
 Oxygen required
 No oxygen
 Cells of the body
 Produces less energy
used: glucose,
fatty acids, and
amino acids
 Glucose and
oxygen turn into
energy, carbon
dioxide, and
water
GLYCOLYSIS
1st part of reactions in cellular respiration - in the cytosol
Breaking down glucose into two pyruvic acid molecules
Released energy used to form ATP and NADH
Consumes and releases ATP, needs the energy to start reaction
http://science.halleyhosting.com/sci/ibbio/cellenergy/resp/respirpics/glycolysis1.gif
Fermentation - when the pyruvate molecules are turned
into waste products and no more energy is produced
Lactic Fermentation
Alcoholic Fermentation
- Happens in fungi, bacteria, yogurt
- Happens in yeast and bacteria
and sometimes muscle
- The pyruvate that accumulates as
- Fermentation forms ethyl
alcohol and carbon dioxide
the result of glucose can be
converted to lactic acid
By, Ayanna R
ATP: Energy Currency of a
Cell
•
•
•
•
•
“ATP” stands for Adenosine triphosphate.
It provides energy to the cell (and the organism!).
The breakdown of glucose, also known as oxidation-reduction,
produces ATP.
The production of ATP looks like this:
Adenosine diphosphate + inorganic Phosphate + energy = ATP
ATP works like “rechargeable batteries.”
ATP: Energy Currency of a
Cell
•
•
•
ATP is released when this chemical reaction takes place:
ATP produces Adenosine diphosphate + energy + inorganic Phosphate
We get energy from ATP by breaking the bonds between the last two
phosphates in the ATP chain.
Then the cycle starts all over again!
ATP: Energy Currency of a
Cell
•
•
•
•
•
“ATP” stands for Adenosine triphosphate.
It provides energy to the cell (and the organism!).
The breakdown of glucose, also known as oxidation-reduction,
produces ATP.
The production of ATP looks like this:
Adenosine diphosphate + inorganic Phosphate + energy = ATP
ATP works like “rechargeable batteries.”
Krebs Cycle!!!
The Krebs Cycle is the
process that pyruvic acid goes
through to be broken down into CO2.
As the pyruvic acid enter the
mitochondrion of a cell, a removed
carbon forms CO2, and removed
electrons change NAD+ to NADH.
Coenzyme A joins the 2-carbon
molecule to form acetyl-CoA. This
acetyl-CoAthen adds the 2-carbon
acetyl group to a 4-carbon
compound, thus forming citric acid.
As the citric acid
proceeds through the cycle, it is first
broken down into a 5-carbon
compound, and then into a 4-carbon
compound. Simultaneously, two
other CO2 molecules are released,
and NAD+ and FAD join with
electrons, forming NADH and
FADH2.
•
•
•
•
•
Pyruvic acid is broken down into
CO2.
Pyruvic acid enters the
mitochondrion of a cell, a
removed carbon forms CO2,
(forms C-C molecule)
removed electrons change
NAD+ to NADH.
Coenzyme A joins the 2-carbon
molecule to form acetyl-CoA,
used to make citric acid.
Two other CO2 molecules are
released, and NAD+ and FAD
join with electrons, forming
NADH and FADH2.
Krebs Cycle!!!
Electron Transport Chain
(ETC)
What?
3rd stage of cellular
respiration
When?
After the Krebs Cycle
Where?
Mitochondria
http://hyperphysics.phy-astr.gsu.edu/hbase/biology/imgbio/eltranmit.gif
What’s happening?
High energy electrons are used to convert ADP to ATP
 Part A:
Electrons move down
a line of carrier
proteins, then form
water with excess O
and H ions
• Part B:
Electrons moving
transport H+ ions
across the membrane.
The inside = +
The outside = -
•Part C:
H+ ions go through ATP
synthases, making them
spin.
The spinning grabs an
ADP and a phosphate,
making ATP!
http://fhs-bio-wiki.pbworks.com/f/1259628320/electron_transport_chain.jpg
Electron Transport Chain
The electron transport chain (etc) is what changes ADP to
ATP using high energy electrons from the krebs cycle. (The
krebs cycle is the series of energy extracting reactions that
breaks down pyruvic acid into CO2.)
How
ATP
links
matter
to
energy:
 ATP is adenosine triphosphate (the most basic, but
useful energy source of all cells)
 ADP is adenosine diphosphate
 ATP synthase= protein spheres found in inner
membranes of mitochondria
Skeletal muscles are
muscles attached to bones. They have alternating
light and dark bands called striations and many
nuclei. They are responsible for voluntary
movements.
Smooth muscles are
found in the walls of the stomach, blood vessels
and intestines. Are spindle-shaped, not striated,
have one nucleus. Not under voluntary control,
responsible for dilating eyes and moving food
through digestive tract.
Only found in the heart.
Striated, smaller cells, usually have one nucleus
but may have two. Non-voluntary.
Skeletal Muscles
• The Skeletal Muscles are attached to the bones.
• Skeletal Muscles are responsible for specific
movements such as typing, dancing, or winking an
eye.
• Most Skeletal Muscles are controlled by the
nervous system.
• Skeletal Muscles are large and have many nuclei.
Smooth Muscles
 Smooth Muscles have one Nucleus.
 Found in the walls of hollow structures such as the stomach, broad
vessels, and the intestines.
 Smooth Muscles move food through the digestive tract and controls
the way blood flows through the circulatory system.
 Smooth Muscles also decreases the size of the pupils when bright light
is being shown onto the eyes.
 Connected together by gap junctions.
Cardiac Muscle
 Found in the heart.
 Connected together by gap junctions.
 Cardiac muscles flex automatically to squeeze the walls of
the heart inward so that the heart beats.
Where
is
energy
stored?
Energy is stored in muscle and
tissue in the form of carbohydrate
glycogen. This energy (ATP) can
be used physically for a duration
of about 15-20 minutes.
MUSCLE FATIGUE
-the decline in ability of a muscle to generate force.
Muscle Fatigue and Work in Antagonistic Pairs
Muscle FatigueMuscles capacity to produce max. voluntary action is reduced
Result of the muscle exceeding tissue substrate and oxygenation capacity.
Muscle Work in Antagonistic PairsWhen one muscle contracts, the other relaxes
(and vice versa)
Disadvantages and
Advantages
Hydroskeleton

Fluid Shape: Fits through
oddly shaped passages.

Strength: Can pry open
by squeezing and
expanding. Does not
have lifting capacity.


Fragility: Fluid must be
incased to work properly.
E x o s k e le t o n

Provides bony plate of
armor for support and
protection of soft internal
tissues and organs.

Limits animal size.

Inflexible

Good leverage for the pull
of muscles.

During molts animals are
extremely vulnerable.
Healing is fast.
Endoskeleton
•Less protective, usually under
the muscle and soft tissue.
•Leverage is worse
•Can support great size and
weight without become too heavy.
•Grows fairly smoothly and evenly,
no molting
Hydrostatic Skeleton
 Lack of permanently rigid structures
 No Support
 Lack of speed
Exoskeleton
 Not much movement
 Blood prevents anything that has an exoskeleton from being on
their backs to long
Endoskeleton
 Can’t mold or shed
 Can be hurt by damage and pollution
Exoskeleton
Hydrostatic Skeleton
Endoskeleton
Advantages
 Hydroskeleton- flexible ,
able to move in tight
spaces, and strong
muscles, body can
change shapes.
 Exoskeleton- External
skeleton, hard body
covering made of
chitin,pretty stable
muscles, a suit of armor
that protects and
supports its body
 Endoskeleton- calcified
plates for animals and
bones for humans,
protection from plates
and bones and harder
to be taken down, have
irregular and bumpy
texture for animals.
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