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. Example: those candies that you break apart and they have the little pieces of candy in them. 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 Energy Adenosine diphosphate (ADP) + Phosphate Adenosine triphosphate (ATP) Partially charged battery 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 LIGHT WATER The “photo” part! LIGHT WATER Purpose: to take sunlight and turn it into chemical energy (ATP) LIGHT REACTIONS 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

NADP+ ADP Light Reactions Calvin Cycle H2O CO2 Light NADP+ ADP P i Light Reactions Calvin Cycle ATP NADPH Chloroplast [CH2O] (sugar) O2

Photosynthesis (continued) Light Dependent Light Independent 1._____________ 2._____________ REACTION REACTION (Calvin Cycle) NEED: NEED: PRODUCES: PRODUCES: PURPOSE: PURPOSE: Light / water ATP / CO2 Oxygen / ATP glucose H2O To change light to chemical energy ATP To make glucose From ATP and CO2 O2

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

Photosynthesis ENERGY #1 Source of Energy = _____________ Cell Energy = _____________ “ ____________ ____________” Who  P Adenine Ribose Phosphate Where  Job to make __________+__________ Energy stored in bond Plants take in . Plants put out . ENERGY Release Energy  Store Energy  Remove –P leaves A-P-P ADP Reactant (in) Product (out) Which has more Energy? ____________ Why- Sun E  Chem EFood E Made in the ____________________

Photosynthesis ENERGY Sun #1 Source of Energy = _____________ ATP Cell Energy = _____________ “ ____________ ____________” Adenosine triphosphate Who  Plants P Adenine Ribose Phosphate Where  Chloroplasts food oxygen Job to make __________+__________ Energy stored in bond Plants take in . Plants put out . ENERGY Release Energy  Break bond O2 CO2 Store Energy  Make bond H2O C6H12O6 Sun E Remove –P leaves A-P-P ADP Reactant (in) Product (out) Remove –P leaves A-P AMP 6CO2 + 6H20 + E  6O2 +C6H12O6 ATP Which has more Energy? ____________ Why- More P-P bonds Sun E  Chem EFood E mitochondria Made in the ____________________

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 Figure 36.16 An open stoma (left) and closed stoma (LMs)

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 WHO??  ALL living organisms!! 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!

Electrons carried via NADH ATP Substrate-level phosphorylation Fig. 9-6-1 Electrons carried via NADH Glycolysis Glucose Pyruvate Cytosol Figure 9.6 An overview of cellular respiration ATP Substrate-level phosphorylation

Electrons carried via NADH Electrons carried via NADH and FADH2 Fig. 9-6-2 Electrons carried via NADH Electrons carried via NADH and FADH2 Glycolysis Citric acid cycle Glucose Pyruvate Mitochondrion Cytosol Figure 9.6 An overview of cellular respiration ATP ATP Substrate-level phosphorylation Substrate-level phosphorylation

Electrons carried via NADH Electrons carried via NADH and FADH2 Fig. 9-6-3 Electrons carried via NADH Electrons carried via NADH and FADH2 Oxidative phosphorylation: electron transport and chemiosmosis Glycolysis Citric acid cycle Glucose Pyruvate Mitochondrion Cytosol Figure 9.6 An overview of cellular respiration 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 Inputs Outputs 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

2. Citric Acid Cycle Pyruvate CO2 NAD+ CoA NADH + H+ Acetyl CoA CoA Fig. 9-11 2. Citric Acid Cycle Pyruvate CO2 NAD+ CoA NADH + H+ Acetyl CoA CoA CoA Citric acid cycle 2 CO2 Figure 9.11 An overview of the citric acid cycle FADH2 3 NAD+ FAD 3 NADH + 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)

Electron transport chain 2 Chemiosmosis Fig. 9-16 H+ H+ H+ H+ Protein complex of electron carriers Cyt c V Q   ATP synthase  2 H+ + 1/2O2 H2O FADH2 FAD NADH NAD+ ADP + P ATP Figure 9.16 Chemiosmosis couples the electron transport chain to ATP synthesis i (carrying electrons from food) H+ 1 Electron transport chain 2 Chemiosmosis Oxidative phosphorylation

INTER- MEMBRANE SPACE H+ ATP synthase ADP + P ATP MITO- CHONDRIAL Fig. 9-UN7 INTER- MEMBRANE SPACE H+ ATP synthase ADP + P ATP i MITO- CHONDRIAL MATRIX H+

Fig. 9-17 CYTOSOL Electron shuttles span membrane MITOCHONDRION 2 NADH or 2 FADH2 2 NADH 2 NADH 6 NADH 2 FADH2 Glycolysis Oxidative phosphorylation: electron transport and chemiosmosis 2 Pyruvate 2 Acetyl CoA Citric acid cycle Glucose + 2 ATP + 2 ATP + about 32 or 34 ATP Figure 9.17 ATP yield per molecule of glucose at each stage of cellular respiration About 36 or 38 ATP Maximum per glucose:

COMPARISON Food synthesized Food broken down Photosynthesis Cellular Respiration Food synthesized Food broken down Energy from the sun stored in glucose Energy of glucose released Oxygen given off Oxygen taken in Produces sugars from and oxygen Produces CO2 and H2O Requires light Does not require light 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

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

(a) Alcohol fermentation Fig. 9-18a 2 ADP + 2 P 2 ATP i Glucose Glycolysis 2 Pyruvate 2 NAD+ 2 NADH 2 CO2 + 2 H+ Figure 9.18a Fermentation 2 Acetaldehyde 2 Ethanol (a) Alcohol fermentation

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

(b) Lactic acid fermentation Fig. 9-18b 2 ADP + 2 P 2 ATP i Glucose Glycolysis 2 NAD+ 2 NADH + 2 H+ 2 Pyruvate Figure 9.18b Fermentation 2 Lactate (b) Lactic acid fermentation

but 2 ATP (with the help of glycolysis) Recap!! Glycolysis: 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 Anaerobic Oxygen No oxygen Makes 36+ ATP Makes 0 ATP but 2 ATP (with the help of glycolysis)

Cell Respiration Mitochondria (1st Step) Occurs in the cytoplasm Breaking down Organic compounds to make ATP (energy) to be used by the cell. Enters the cell by Facilitated Diffusion 2 ATP (in) (1st Step) Occurs in the cytoplasm 4 ATP(out) If enough O2 If NOT enough O2 Mitochondria

Cell Respiration Mitochondria Pyruvic Acid C6H12O6 2 ATP 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 2 ATP (in) Glycolysis (1st Step) Occurs in the cytoplasm 4 ATP(out) Pyruvic Acid If enough O2 If NOT enough O2 Aerobic Respiration Anaerobic Respiration 2 ATP Alcoholic Fermentation Kreb Cycle Lactic Acid Fermentation Mitochondria CO2 34 ATP CO2 Ethanol ETC Lactic Acid H2O

Cellular Respiration Aerobic Anaerobic Where Job to make ________ IN OUT Also called ______ Lactic Acid Fermentation Reactant (In) Product (Out) Notice: Alcoholic Fermentation CO2 O2 Food Cellular Respiration Photosynthesis

Cellular Respiration Aerobic Anaerobic oxygen No oxygen Where mitochondria Makes 38 ATP Makes 2-4 ATP Job to make ________ ATP IN OUT Also called ______ O2 CO2 fermentation C6H12O6 H2O E-ATP Lactic Acid Fermentation Reactant (In) Product (Out) Glucose  Energy + Lactic Acid 6O2 +C6H12O6 6CO2 + 6H20 + E Does not produce as much energy as aerobic Respiration Products of Photosynthesis are reactants in Cellular Respiration Notice: Alcoholic Fermentation CO2 Glucose Ethanol + Carbon Dioxide + Energy O2 Performed by yeast, utilized in the production of alcohol. Food Cellular Respiration Photosynthesis