Global warmingGlobal warmingSince the last ice age, carbon dioxide levels have increased
continually. The increase of carbon dioxide over the last 150 years has been much more dramatic going from 280 parts per million (PPM) to 400 PPM. This has had obvious effects on the global temperature averages as the ten hottest years on record occurred from 1998 to now. The ten hottest years ever were:1. 20102. 20053. 19984. 20135. 20036. 20027. 20068. 20099. 200710. 2004
Cellular EnergeticsCellular Energetics
How cells obtain and use energy How cells obtain and use energy through the processes of through the processes of
photosynthesis and cellular photosynthesis and cellular respirationrespiration
IV. Cellular EnergeticsIV. Cellular Energetics
A.A. Energy - ability to do workEnergy - ability to do work1.1. Cells use an energy-storing compound known as Cells use an energy-storing compound known as
ATP to provide the energy to do workATP to provide the energy to do work2.2. ATP = Adenosine TriphosphateATP = Adenosine Triphosphate
a.a. Energy is stored in the bonds between phosphate Energy is stored in the bonds between phosphate groupsgroups
b.b. Energy is released when bonds are brokenEnergy is released when bonds are brokenc.c. ATP becomes ADP when a phosphate is lostATP becomes ADP when a phosphate is lostd.d. ATP is recyclableATP is recyclablee.e. Cells regenerate ATP through the process of cellular Cells regenerate ATP through the process of cellular
respiration which is reliant on photosynthesisrespiration which is reliant on photosynthesis
CO2
H2O
Glucose
O2
ATP
ECOSYSTEM
Sunlight energy
Photosynthesis in chloroplasts
Cellular respiration in mitochondria
(for cellular work)
Heat energy
3.3. Obtaining energyObtaining energya. Autotrophs – organisms capable of using a source of
energy to produce food molecules from inorganic molecules in the environmenti. Photoautotrophs – capture light energyii. Chemoautotrophs – absorb other inorganic molecules to
produce own food
b. Heterotrophs – organisms that obtain energy from the consuming of other organisms
B. Cellular Respiration1. Autotrophs and heterotrophs must be able to release energy
from the carbohydrates produced during photosynthesis2. During cellular respiration, glucose is broken down in a step-
by-step process to release the energy stored in its bonds3. The energy from the breakdown of glucose is used to
generate ATPs4. Chemical equation
C6H12O6 + 6O2 ----> 6CO2 + 6 H2O + ENERGY (ATP)
5. Occurs in the cytoplasm and the mitochondrion
NADH
NADH FADH2
GLYCOLYSISGlucose Pyruvate CITRIC ACID
CYCLE
OXIDATIVE PHOSPHORYLATION (Electron Transport and Chemiosmosis)
Substrate-level phosphorylation
Oxidative phosphorylation
Mitochondrion
and
High-energy electrons
carried by NADH
ATPATPATP
CO2 CO2
Cytoplasm
Substrate-level phosphorylation
6. Reactionsa. Glycolysis
i. Takes place in the cytoplasmii. The initial splitting of a glucose moleculeiii. Produces two pyruvatesiv. Process requires energy (2 ATP) to break apart glucose and
produces 4 ATPv. Breaking of bonds releases energized electrons which are
accepted by a molecule known as NAD+
vi. NAD+ is converted to NADH to carry electrons to the electron transport chain in the mitochondrion
vii. If oxygen is present, the pyruvates can enter the mitochondrion (aerobic)
viii. If oxygen is absent, the pyruvates will remain in the cytoplasm (anaerobic)
b. Krebs Cyclei. Takes place in the mitochondrionii.Two pyruvates enter the mitochondrion and are further broken
down to release energyiii. As pyruvate is gradually broken down,
carbon dioxide is released as a waste product and released electrons are accepted by more NAD+ and an additional molecule known as FAD
iv. Produces 1 ATP for every cycle (2 ATP total)
c. Electron Transport Chaini. Takes place in the inner mitochondrial membraneii. Energized electrons from the broken bonds of glucose and pyruvate
provide the energy to produce ATPsiii. NADH and FADH2 transfer electrons to an ETC
in the inner mitochondrial membraneiv. Energy from the electrons activates proton
pumps, building a proton concentration gradient across the membranev. Protons pass through ATP synthase, a tranport protein/enzyme that
produces ATPvi. As protons pass through, ADP is converted into
ATPvii. Produces up to 34 ATP
d. Overall process produces a total of 36 – 38 ATP
Intermembrane space
Inner mitochondrial membrane
Mitochondrial matrix
Protein complex
Electron flow
Electron carrier
NADH NAD+
FADH2 FAD
H2OATPADP
ATP synthase
H+ H+ H+
H+
H+H+
H+
H+
H+
H+
H+
H+
H+
H+
P
12
O2
Electron Transport Chain Chemiosmosis
.
OXIDATIVE PHOSPHORYLATION
+ 2
H+
H+
H+
H+
H+
H+ H+ H+ H+
H+
H+
H+
H+
O2
H2OP ATP
NADH NAD+
FADH2 FAD
Rotenone Cyanide, carbon monoxide
Oligomycin
DNP
ATPSynthase
12
2
ADP
Electron Transport Chain Chemiosmosis
7. Fermentation - Breaking down glucose without oxygena. Occurs in the cytoplasmb. Otherwise known as anaerobic respirationc. Begins with glycolysisd. Only produces 2 ATPe. Purpose is to regenerate NAD+f. Two types
i. Lactic acid fermentationA. Pyruvate is converted into
lactic acidB. Occurs in muscle cells
ii. Alcoholic fermentationA. Pyruvate is converted to ethyl
alcoholB. Occurs in yeast cells
C. PhotosynthesisC. Photosynthesis1. Conversion of sunlight energy into chemical energy
stored in the bonds of carbohydrates and other organic molecules
2. Chemical equationlight
6CO2 + 6H2O ----> C6H12O6 + 6O2
3. Occurs in the chloroplasta. Thylakoid – photosynthetic membrane diskb. Granum – stack of thylakoidsc. Stroma – space between the thylakoids and the outer
membranes of the chloroplast4. Pigments – substance capable of absorbing and
reflecting light energya. Chlorophylls – primary pigmentb. Carotenoidsc. Xanthophylls
5. 5. Reactionsa. Light reactions
i. Capture of sunlight energy to produce temporary energy-storing compounds (ATP and NADPH)
ii. Occurs in the thylakoidsiii. Light is absorbed by photosystems – clusters of pigment
molecules in the thylakoidsiv. Electrons in pigment molecules are “excited” to higher
energy levels
5.5. ReactionsReactionsa.a. Light reactionsLight reactions
v. “Excited” electrons are passed along a series of membrane proteins known as the electron transport chain (ETC) in the thylakoid membrane
vi. Energy from electrons is used to generate ATPvi. Energy from electrons is used to generate ATP- Energy from the electrons activates proton pumps, building a proton concentration gradient as hydrogen ions (protons) are pumped across the membrane- Protons pass through ATP synthase, a transport protien/enzyme that produces ATP- As protons pass through, ADP is converted into ATP
vii. Electrons are eventually passed to an energy-storing molecule known as NADPH
viii. Water is split to replenish electrons in pigment moleculesviii. Water is split to replenish electrons in pigment moleculesix. As water splits, electrons are donated to chlorophyll and oxygen gas is
released
5.5. ReactionsReactionsb. Dark reactions
i. Otherwise known as the Calvin Cycleii. Energy from the ATP and NADPH produced in the light
reactions is used to produce organic molecules from carbon dioxide
iii. Occurs in the stroma