c9- energy in a cell
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C9- Energy in a Cell. Pp. 220-249. Table of Contents. Section 9.1-The Need for Energy Section 9.2- Photosynthesis: Trapping the Sun’s Energy Section 9.3- Getting Energy to Make ATP. 9.1-The Need for Energy. Essential for life - PowerPoint PPT PresentationTRANSCRIPT
C9- Energy in a Cell
Pp. 220-249
Table of Contents
Section 9.1-The Need for EnergySection 9.2-
Photosynthesis: Trapping the Sun’s Energy
Section 9.3- Getting Energy to Make ATP
9.1-The Need for Energy
Essential for life Active transport, cell division, movement, &
production, transport & storage of proteins require energy.
Energy molecule ATP adenosine triphosphate
Forming & Breaking Down ATP
Phosphate groups are positive so they repel each other.
Bonding them requires an input of energy.AMP adenosine monophosphate 1 groupADP adenosine diphospate 2 groupsATP With 3 groups, breakdown releases even moreenergy.
Forming & Breaking Down ATP
ATP With 3 groups, breakdown releases even more energy.
ADP-ATP cycle is renewable
The cell doesn’t have to store all the energy it needs.
Forming & Breaking Down ATP
When ATP is broken down to ADP, it can be released from the binding site in the protein and be made available to another ATP.
Uses of Cell Energy
Making new molecules
Building cell membranes & organelles
To maintain homeostasis
To eliminate waste Transmit nerve
impulses
9.2 Photosynthesis
Trapping Energy from Sunlight Process of changing sunlight to glucose in 2 steps
Light Dependent RXN converts it to chemical E in form of ATP
Light Independent RXN uses ATP to make glucose
9.2 Photosynthesis
Photosynthesis- light-dependent
Occurs in the chloroplast in the membranes of the thylakoid discs
Pigment chlorophyll absorbs light (reflects green)
Photosynthesis- light-dependent
Energy from light is transferred to electrons
Electron are passed to a series of proteins or electron transport chain
Water is split to release oxygen; H ion joins carrier molecule NADP (photolysis)
Photosynthesis- light-dependent
NADPH transfers energy to stroma
H ions are pumped into thylakoid & provide energy for ATP or chemiosmosis
Second Phase is light independent-
The Calvin Cycle
Photosynthesis- light-independent
o The Calvin Cycleo Series of carbon
dioxide reactions to form sugar.
o C atom from CO2 bonds w/ 5 carbon sugar ribulose. (Carbon fixation)
o 6C sugar divides into 2 3C sugars
Photosynthesis- light-independent
o Calvin Cycleo bonds w/ 5 carbon
sugar ribulose.o 6C sugar divides into
2 3C sugarso Series of rxn convert
3C molecules into higher energy PGAL (phosphoglyceralde-hyde)
Photosynthesis- light-independent
o Calvin Cycleo Series of rxn convert
3C molecules into higher energy PGAL (phosphoglyceralde-hyde)
o 5 PGAL make 3 RuBP to replenish what was used so process can continue
9.3 Getting Energy to Make ATP
Cellular respiration- process that mitochondria use to break down food molecules to ATP.
3 stages of respiration Glycolysis Citric Acid Cycle Electron Transport
Chain
Respiration
Glycolysis series of chemical reactions in cytoplasm to break glucose (6C) to pyruvic acid (3C).
Anaerobic process Takes 2 ATP to start glycolysis but only makes 4 ATP. Not effective
Respiration
Glycolysis uses an electron carrier, NAD+, which forms NADH when it accepts 2 electrons.
After glycolysis, the PGAL moves into the mitochondria where 2 more stages occur.
Respiration
Citric Acid Cycle (Krebs)- another series of chem RxNs changing acetyl-CoA (2C) to form ATP & CO2. NAD+ & FAD pick up energized electrons & pass them to ETC.
Respiration
Electron Transport Chain- inner membrane of the mitochondria- energized electrons are passed from protein to protein releasing energy as they go.
Respiration
Electron Transport Chain- some energy is used to make ATP & some is used to pump H+ into mitochondrion center
Final e acceptor is O which reacts w/ H to form 2 water molecules
Overall, 32 ATP made aerobicly + 4= 36 total
Fermentation
Anaerobic process to produce ATP w/out oxygen during heavy exertion.
Two types: Lactic acid fermentation Alcoholic fermentation
Fermentation
Lactic Acid Fermentation- supplies energy when O is scarce
2 pyruvic acids use NADH to make 2 lactic acid molecules. 2 ATP formed for each glucose and lactic acid goes to the muscle cells & on to the liver to be broken into pyruvic acid.
Lactic acid causes muscle fatigue.
Fermentation
Alcoholic fermentation- used by yeast cells & some bacteria to produce CO2 & ethyl alcohol.
CO2 produced by yeast makes bread rise.
Comparing Photosynthesis & Respiration
Food synthesized Sun’s energy stored CO2 used Oxygen given off Requires light Produces sugars Food broken down Glucose energy released CO2 produced Oxygen used Does not need light Produces CO2 & water