Download File

ENERGY
EATING!
When we
eat, our
food is
broken down
in our bodies
to get
energy out.
Energy – The ability to do
work
Where does energy come from?? Food
Energy in food comes from? SUN
Chemical Energy
• Living things use chemical energy.
–ATP (adenosine triphosphate) –
chemical compound that cells use
to store and release energy.
***All organisms must have ATP
in order to function.
ATP
• ATP – The universal energy molecule for
all cells.
• ATP stands for Adenosine Triphosphate
• A molecule made of 5 smaller molecules
bonded together:
– Adenine
– Ribose
– 3 phosphate groups
How does ATP give cells energy?
Energy is released by breaking the bonds.
ENERGY!!!
Energy Cycle
• ADP (adenosine
diphosphate) – consists
of adenine, ribose, and
2 phosphate groups
• Energy is continuously
cycled in the
biochemical pathway as
ATP is converted to
ADP and then ADP is
converted into ATP.
It is recharged
ADP uses energy and gains an extra P
and is recharged back to ATP
ADP
ATP
Energy
Adenosine diphosphate (ADP) + Phosphate
Partially
charged
battery
Energy
Adenosine triphosphate (ATP)
Fully
charged
battery
ATP Summary
• Energy is released when the
phosphate bonds are broken.
• Energy is stored (ATP rebuilt) when
the phosphate bonds are formed.
• ***All organisms must have ATP in
order to function.
Chemical Reactions are Always
Occurring in Cells!
• Reactants: Substances that are used
during a chemical reaction.
• Products: The substances made after a
chemical reaction.
• The sum total of all chemical reactions
occurring in a cell is called the cell’s
METABOLISM
Energy is taken in, stored and
used differently by different
organisms
• Light energy from the sun is used
by plants to make glucose in a
process called photosynthesis
• Energy from glucose is used by
organisms to make more energy
in a process called cellular
respiration.
Plants and some other types of organisms
are able to use light energy from the
sun to produce food.
• Autotrophs: organisms that make their
own food (Ex. Plants)
• Heterotrophs: obtain energy from the
food they consume (ex. People).
Photosynthesis
& The Leaf
Overview
• Who? 
plants
• Where? 
chloroplast
Photosynthesis
** If any of the reactants are missing 
photosynthesis will not occur.
Pigments – capture light energy
• Chlorophyll – the main
pigment found in most
producers.
– Absorbs red and violet
light; reflects greens
and yellows.
– Located in the
chloroplasts of plants
and algae
– Other pigments reflect
colors such as reds,
yellows, and oranges
(leaves and fruits)
Inside the chloroplast
• Thylakoids –
membranes that
contain chlorophyll
and proteins that
absorb light
• Stroma: liquid
portion inside
chloroplast
Two steps of photosynthesis
1. Light Dependent Reactions
-Where?  Thylakoid Membranes
-What?  Sunlight is absorbed by
chlorophyll (excites electrons) and
water is split by light.
-Why?  to provide ATP for step
2!
Light Reactions
The “photo” part!
LIGHT
WATER
LIGHT
REACTIONS
Purpose: to take
sunlight and turn
it into chemical
energy (ATP)
Needs chlorophyll!
ATP
OXYGEN
2. Light independent
reactions (Calvin Cycle) (Dark
reactions)
-Where?  stroma
-What?  Takes ATP from
step 1 and CO2 and makes
GLUCOSE!
Calvin Cycle (Dark Reaction)
The “synthesis” part
CARBON
DIOXIDE
ATP
Purpose: to
take carbon
dioxide and
make glucose
CALVIN CYCLE
GLUCOSE
CO2
H2O
Light
NADP+
ADP
P
i
Light
Reactions
Calvin
Cycle
ATP
NADPH
Chloroplast
O2
[CH2O]
(sugar)
Photosynthesis (continued)
CO2
Light
Dependent
1._____________
REACTION
NEED:
Light / water
PRODUCES:
Oxygen / ATP
H2O
O2
Light
Independent
2._____________
REACTION
(Calvin Cycle)
NEED:
ATP / CO2
PRODUCES:
glucose
PURPOSE:
PURPOSE:
To change light
To make glucose
to chemical energy
From ATP and
ATP
CO2
Photosynthesis
• Who  Plants
• Where  Chloroplast
• Job – to make food and oxygen
• Plants take in….water, carbon
dioxide, sunlight
• Plants put out….oxygen, glucose
CO2
O2
Light
H2O
Sugar
O2
H2O
and minerals
CO2
#1 Source of Energy = _____________
Cell Energy = _____________
“ ____________ ____________”
Who 
Adenine
Where 
Phosphate
P
P
P
Job to make __________+__________
Ribose
Plants take in
Plants put out
Release Energy 
•.
•.
Store Energy 
•.
•.
•.
Remove –P leaves A-P-P ADP
Reactant (in)
Product (out)
Which has more Energy? ____________
WhyMade in the ____________________
Sun E  Chem EFood E
Sun
#1 Source of Energy = _____________
ATP
Cell Energy = _____________
Adenosine triphosphate
“ ____________
____________”
Who 
Adenine
Where  Chloroplasts
Phosphate
P
P
Plants
P
food
oxygen
Job to make __________+__________
Ribose
Release Energy  Break bond
Store Energy 
Make bond
Plants take in
Plants put out
•. CO2
•. O2
•. H O
2
•. C H O
6 12 6
•.
Remove –P leaves A-P-P
Remove –P leaves A-P
ADP
AMP
ATP
Which has more Energy? ____________
Why-
More P-P bonds
mitochondria
Made in the ____________________
Sun E
Reactant (in)
Product (out)
6CO2 + 6H20 + E  6O2 +C6H12O6
Sun E  Chem EFood E
Leaves and leaf
parts
Mesophyll
• Ground tissue in leaves
(meso = middle, phyll = leaf)
• Contains chloroplasts
Mesophyll
Mesophyll
Xylem and Phloem
• Xylem – carries water
• Phloem – carries nutrients
Stomata (singular – stoma)
• Tiny openings in the underside of the
leaf – function – gas exchange!
Guard Cells
• Cells that open and close the
stomata
Fig. 36-16
Guard cells turgid/Stoma open
Guard cells flaccid/Stoma closed
(a) Changes in guard cell shape and stomatal opening and
closing (surface view)
Epidermis
• Outer layer of leaf cells.
Cuticle
• Waxy covering of leaf
Factors that affect the rate of
photosynthesis
• Amount of sunlight
• Amount of water
• Amount of carbon dioxide
Chemosynthesis
Chemosynthesis: The process by which some organisms, such
as bacteria, produce energy through a chemical reaction.
Ex. Organisms found near deep sea hydrothermal vents use
hydrogen sulfide coming out of seafloor in vent fluids to
create energy.
Equation:
Hydrogen sulfide chemosynthesis:
CO2 + O2 + H2S → CH2O + S + H2O
How do our bodies take food and
make it into energy?
What types of organisms undergo
cellular respiration?
Cellular respiration occurs in ALL living cells!
What are some of the things that our body
does that requires energy?
Physical Activities
•Running
•Playing sports
•Pumping our hearts
Cellular Activities
•Sending messages to our brain
•Transporting molecules in and
out of our cells
Cellular
Respiration
Cellular Respiration
 The process by which food
(glucose) is broken down to
produce ATP
WHO??  ALL living
organisms!!
Aerobic Respiration
C6H12O6 + 6O2  6CO2 + 6H2O + E
Aerobic – WITH OXYGEN!
Fig. 9-6-1
Electrons
carried
via NADH
Glycolysis
Pyruvate
Glucose
Cytosol
ATP
Substrate-level
phosphorylation
Fig. 9-6-2
Electrons carried
via NADH and
FADH2
Electrons
carried
via NADH
Citric
acid
cycle
Glycolysis
Pyruvate
Glucose
Mitochondrion
Cytosol
ATP
ATP
Substrate-level
phosphorylation
Substrate-level
phosphorylation
Fig. 9-6-3
Electrons carried
via NADH and
FADH2
Electrons
carried
via NADH
Citric
acid
cycle
Glycolysis
Pyruvate
Glucose
Oxidative
phosphorylation:
electron transport
and
chemiosmosis
Mitochondrion
Cytosol
ATP
ATP
ATP
Substrate-level
phosphorylation
Substrate-level
phosphorylation
Oxidative
phosphorylation
1. GLYCOLYSIS
• Glycolysis (“splitting of sugar”)
breaks down glucose into two
molecules of pyruvate
• Glycolysis occurs in the
cytoplasm
Glycolysis
• Anaerobic – no oxygen
• Glucose broken down to Pyruvic
Acid
• Uses 2 ATP, makes 4 ATP
• Net ATP is 2
• Not very effective
Fig. 9-UN5
Outputs
Inputs
2
ATP
Glycolysis
+
2 NADH
Glucose
2
Pyruvate
After Glycolysis…
•In the presence of
O2, pyruvate
enters the
mitochondrion
2. Citric Acid Cycle (AKA Kreb
cycle)
• Series of steps to modify the
pyruvate and create ATP…in this
process CO2 is released as
waste.
• 2 ATP made
Fig. 9-11
Pyruvate
CO2
NAD+
CoA
2. Citric
Acid Cycle
NADH
+ H+
Acetyl CoA
CoA
CoA
Citric
acid
cycle
FADH2
2 CO2
3 NAD+
3 NADH
FAD
+ 3 H+
ADP + P i
ATP
3. The Electron Transport Chain
•Electrons fall down a
gradient and are used to
create ATP
•Produces 32 ATP
So: AEROBIC
RESPIRATION PRODUCES
36-38 ATP (very effective)
Fig. 9-16
H+
H+
H+
H+
Protein complex
of electron
carriers
Cyt c
V
Q


ATP
synthase

FADH2
NADH
2 H+ + 1/2O2
H2O
FAD
NAD+
ADP + P i
(carrying electrons
from food)
ATP
H+
1 Electron transport chain
Oxidative phosphorylation
2 Chemiosmosis
Fig. 9-UN7
INTERMEMBRANE
SPACE
H+
ATP
synthase
ADP + P i
MITOCHONDRIAL
MATRIX
ATP
H+
Fig. 9-17
Electron shuttles
span membrane
CYTOSOL
2 NADH
Glycolysis
Glucose
2
Pyruvate
MITOCHONDRION
2 NADH
or
2 FADH2
6 NADH
2 NADH
2
Acetyl
CoA
+ 2 ATP
Citric
acid
cycle
+ 2 ATP
Maximum per glucose:
About
36 or 38 ATP
2 FADH2
Oxidative
phosphorylation:
electron transport
and
chemiosmosis
+ about 32 or 34 ATP
COMPARISON
Photosynthesis
Cellular Respiration
Food synthesized
Food broken down
Energy from the sun
stored in glucose
Oxygen given off
Energy of glucose
released
Oxygen taken in
Produces sugars from
and oxygen
Requires light
Produces CO2 and H2O
Occurs only in presence of
chlorophyll and in the chloroplasts of
plants
Occurs in mitochondria of plants and
animals
Carbon Dioxide taken in
Carbon dioxide given off
Does not require light
Anaerobic Respiration
• Occurs when no oxygen is available
• Also called FERMENTATION
• Only produces 2-4 ATP
Alcoholic Fermentation
Glucose  ethanol + CO2 + 2 ATP
• who?? YEAST  used in beer
brewing, wine making, and baking
• Produces: Ethyl Alcohol and CO2
Fig. 9-18a
2 ADP + 2 P i
Glucose
2 ATP
Glycolysis
2 Pyruvate
2 NAD+
2 Ethanol
(a) Alcohol fermentation
2 NADH
+ 2 H+
2 CO2
2 Acetaldehyde
Lactic Acid Fermentation
Glucose  lactic acid + 2 ATP
• Lactic acid fermentation by some
bacteria is used to make yogurt
• Human muscle cells use lactic acid
fermentation to generate ATP when
O2 is scarce
• Produces: soreness/pain in muscles
Fig. 9-18b
2 ADP + 2 P i
Glucose
2 ATP
Glycolysis
2 NAD+
2 NADH
+ 2 H+
2 Pyruvate
2 Lactate
(b) Lactic acid fermentation
Glycolysis:
Recap!!
Process in which one molecule of glucose is broken in half,
it is the first stage of cellular respiration.
Aerobic Process:
Occurs after glycolysis in the presence of oxygen
Anaerobic Process:
Occurs after glycolysis without oxygen
Aerobic
Oxygen
Anaerobic
No oxygen
Makes 36+ ATP
Makes 0 ATP
but 2 ATP (with the help of
glycolysis)
Breaking down Organic
compounds to make
ATP (energy) to be used
by the cell.
Enters the cell
by Facilitated
Diffusion
2 ATP (in)
Occurs in the
cytoplasm
If NOT enough O2
(1st Step)
4 ATP(out)
If enough O2
Breaking down Organic
compounds to make
ATP (energy) to be used
by the cell.
Enters the cell
by Facilitated
Diffusion
C6H12O6
(glucose- organic compounds)
2 ATP (in)
Glycolysis (1st Step)
Occurs in the
cytoplasm
4 ATP(out)
If NOT enough O2
Pyruvic Acid
If enough O2
Aerobic Respiration
Anaerobic Respiration
Kreb Cycle
CO2
CO2
Ethanol
ETC
Lactic
Acid
H2O
Aerobic
Anaerobic
Where
Job to make ________
IN
OUT
•
•
•
•
Also called
______
•
Reactant (In)
Lactic Acid Fermentation
Product (Out)
Notice:
Alcoholic Fermentation
CO2
O2
Food
Photosynthesis
Cellular
Respiration
Aerobic
oxygen
Where mitochondria
Makes 38 ATP
Job to make ________
ATP
IN
OUT
• O2
• CO2
• C6H12O6
• H2O
Anaerobic
No oxygen
Makes 2-4 ATP
Also called
fermentation
______
• E-ATP
Reactant (In)
Lactic Acid Fermentation
Glucose  Energy + Lactic Acid
Product (Out)
6O2 +C6H12O6 6CO2 + 6H20 + E
Notice:
Products of Photosynthesis are
reactants in Cellular Respiration
CO2
Photosynthesis
Alcoholic Fermentation
Glucose Ethanol + Carbon Dioxide + Energy
O2
Food
Does not produce as much energy as
aerobic Respiration
Cellular
Respiration
Performed by yeast, utilized in the
production of alcohol.