SDNT Cell Energetics Cell Energetics CELL RESPIRATION Aerobic

SDNT Cell Energetics

Cell Energetics

CELL RESPIRATION Aerobic Formula: Copy down the formula for cellular respiration shown above.

Chapter Terms (part 1): Endergonic – A rxn that requires energy input Exergonic – A rxn that gives off energy Catabolic – A rxn that breaks down complex molecules Anabolic – A rxn that builds complex molecules Proton Gradient – High H+ concentrations on one side of a membrane & low H+ concentrations on the other side.

Chapter Terms (part 2): Carbon Fixation – The process of making a carbohydrate (sugar) from water and carbon dioxide (CO 2) Glycolysis – “sugar splitting process” Aerobic – “with oxygen” Anaerobic – “without oxygen” Photosynthesis – The process of utilizing energy from light to make sugars (glucose – C 6 H 12 O 6) Chlorophyll – The main light absorbing pigment used by plants for photosynthesis; is green colored

Glycolysis Summary: (copy this) Glucose Sugar: Pyruvate: C-C-C-C Pyruvate: C-C-C 2 CO CO 2 Acetyl-Co A: C-C Citric Acid Cycle

Glycolysis fill-in-the-blank ____1____: ___2__: C-C-C-C ___2__: C-C-C _ 3 _ ____4___: C-C __5__ Cycle

ATP and Cellular Respiration

What Is ATP? “Adenosine Triphosphate” Organic molecule containing highenergy Phosphate bonds Chemical used for energy by all living things

Chemical Structure of ATP Adenine Base 3 Phosphates Ribose Sugar

What Does ATP Do for You? It supplies YOU with ENERGY!

How Do We Get Energy From ATP? By breaking the highenergy bonds between the last two phosphates in ATP

How Does That Happen? An Enzyme!

How is ATP Re-Made? By ATP Synthase (acts like a water the end of the Electron Transport wheel) at Chain ATP Synthase

Outer membrane The Electron Transport Chain

Why do you need to breathe? l OXYGEN is the final electron acceptor in the Electron Transport Chain l If you can’t breathe, you can’t make ATP!

Why do you need to drink water? l Your body uses water to break down ATP for energy l If you don’t have enough water in your cells, those cells can’t use the ATP in them!

What is the Process Called? HYDROLYSIS (Adding H 2 O) H 2 O

Quick facts about Cellular Respiration: l l l You must have OXYGEN to complete Cell Respiration Oxygen is reduced (gains e-) and glucose is oxidized (loses e-) Glucose breakdown is therefore a reduction-oxidation (REDOX) rxn Breakdown of one glucose results in about 36 ATP molecules Exergonic Reaction

Overall Equation for Cellular Respiration C 6 H 12 O 6 + 6 O 2 YIELDS 6 CO 2 + 6 H 20 + 36 ATP’s

What Type of Process is Cellular Respiration? l. A REDOX reaction – A REDOX rxn is one where there is a transfer of electrons from one substance to another. – Remember O. I. L. R. I. G. Oxidation l Reduction l Is Is Losing (electrons) Gaining (electrons)

Other Cellular Respiration Facts: l Metabolic Pathway that breaks down carbohydrates l Process is Exergonic as High-energy Glucose is broken into CO 2 and H 2 O l Process is also Catabolic because larger Glucose breaks into smaller molecules

Cell Respiration

What are the 3 stages of Cellular Respiration? 1. 2. 3. Glycolysis (OUTSIDE the mitochondria) The Citric Acid Cycle (Krebs Cycle) The Electron Transport Chain

What are the 3 stages of Cell Respiration? The 3 Stages:

Where respiration happens: l. In and around the mitochondria of your cells

Review of Mitochondria Structure l Smooth outer Membrane l Folded inner membrane l Folds called Cristae l Space inside cristae filled with cytosol called the Matrix

Where Does Cellular Respiration Take Place? l Specifically, it takes place in three parts of the cell: 1. Cytoplasm 2. Mitochondrial Matrix 3. Mitochondrial Membrane (Cristae)

Cellular Respiration overview:

Cell Respiration Overview: Occurs across Cristae Occurs in Cytoplasm Occurs in Matrix

Fermentation

Lactic Acid Fermentation v Occurs when O 2 NOT present (anaerobic) v. Lactic Acid fermentation takes place in muscle cells under oxygen debt (makes muscle fatigued) v. Lactic acid is mildly toxic to cells and causes soreness and stiffness.

Glycolysis (with O 2) Stage 1: Glycolysis Glucose Sugar: • Glycolysis literally C-C-C-C means “the process Pyruvate: of sugar splitting” C-C-C • In Glycolysis, a six CO carbon sugar 2 (glucose) is broken down so that our Acetyl-Co A: cells can extract the C-C energy contained in Citric it. Acid Cycle

Glycolysis (without O 2) Stage 1: Glycolysis Glucose Sugar: • Glycolysis can go C-C-C-C on even without oxygen, but it is truncated (cut short) and not nearly as efficient. • Lactic Acid Fermentation happens when oxygen is not present. Pyruvate: C-C-C Lactic Acid

Fermentation comparison Advantage: • although only 2 ATP, it provides for quick burst of energy for muscular activity Disadvantage: • lactate is toxic to cells • when blood cannot remove all lactate from muscles, lactate changes p. H and causes muscle fatigue. • Causes oxygen debt, b/c O 2 is still needed after exercising. • Recovery occurs after lactate is sent to liver, converted into pyruvate; then respired/converted to glucose.

Alcohol Fermentation v. Alcoholic fermentation happens in yeast & produces alcohol. v. Nets only 2 ATP v. Too high of an alcohol content can kill the yeast

Fermentation in Industry Yeast would rather do aerobic Rxs; it has 18 x more energy per glucose. l But, anaerobic will keep them alive if oxygen is not present. l Fermentation vats at a brewery

Fermentation in Industry Alcohol Industry – Alcohol is produced through yeast fermentation. l Baking Industry many breads use yeast to provide bubbles (of CO 2) to raise the dough. l

Fermentation in Industry Swiss Cheese: Holes are bubbles of CO 2 from bacterial fermentation.

Photosynthesis (Bellringers)

Bellringer 1 Copy down the formula for Photosynthesis from above:

Bellringer 2 1. Which cells in a plant’s leaves are the primary site for photosynthesis because of their high chloroplast content? 2. What is the name of the hole in the leaf that plants breath through? 3. What is the name for the 2 special cells that regulate how much the plant’s “breathing holes” are open or shut?

Bellringer 2 (answers) 1. Which cells in a plant’s leaves are the primary site for photosynthesis because of their high chloroplast content? • (Mesophyll Cells) 2. What is the name of the hole in the leaf that plants breath through? • (Stoma or Stomata) 3. What is the name for the 2 special cells that regulate how much the plant’s “breathing holes” are open or shut? • (Guard Cells)

Bellringer 3 1. (whole stack) 5. What is the name of this entire structure? 2. (space inside) 4. (fluid) 3. (individual disc)

Bellringer 3 (answers) 1. (whole stack) Granum 5. What is the name of this entire structure? 2. (space inside) Lumen Chloroplast 4. (fluid) Stroma 3. (individual discs) Thylakoids

Bellringer 4 1. Which pigment is primarily responsible for gathering incoming light for use in photosynthesis? 2. What is the range of the visible spectrum of light? 3. Honeybees can see what part of the light spectrum which humans are unable to?

Bellringer 4 (answers) 1. 2. 3. Which pigment is primarily responsible for gathering incoming light for use in photosynthesis? (chlorophyll) What is the range of the visible spectrum of light? (about 400 -700 nm. ) Honeybees can see what part of the light spectrum which humans are unable to? (Ultra-violet or U. V. )

Bellringer 5 t gh Li O 2 Light dependent rxn’s in thylakoids Calvin Cycle (light independent rxn’s) CARBON FIXATION ATP H 2 O Copy down this overview of the light reactions that happen in plants: CO 2 glucose

Bellringer 6 Copy down this overview of the Light Independent reactions that happens in plants. CO 2 ADP + P Light dependent rxn’s in thylakoids Calvin Cycle (Carbon Fix. ) ATP Energy Glucose C 6 H 12 O 6

Bellringer 7 1. What is the name for the cycle that plants undergo to create sugars? 2. Do plants need light for the above process? 3. What is the name of the enzyme that plants use to fix carbon?

Bellringer 7 (answers) 1. What is the name for the cycle that plants undergo to create sugars? (Calvin Cycle) 2. Do plants need light for the above process? (No) 3. What is the name of the enzyme that plants use to fix carbon? (Rubisco)

Bellringer 8 (copy down) t gh Li O 2 CO 2 ADP + P Light dependent rxn’s in thylakoids Calvin Cycle (Carbon Fix. ) ATP H 2 O Photosynthesis Overview Glucose C 6 H 12 O 6

Bellringer 9 (fill-in-the-blank) t gh Li 1. __ 7. __ ADP + P Light 2. __ rxn’s in 5. ___ Cycle 3. ___ (Carbon Fix. ) 4. __ H 2 O Photosynthesis Overview 6. _____ C 6 H 12 O 6

Photosynthesis

Photosynthesis Overview:

Photosynthesis Overview I. Sunlight provides the energy. - Photosynthetic organisms serve as ultimate source of food for life. - Food chain starts w/ photosynthesizers.

Site of Photosynthesis LEAF epidermis mesophyll Stomata epidermis CO 2 enters; O 2 & H 2 O vapor exits

A closer look at chloroplasts 1. Membranes • Outer and Inner 2. Stroma • Fluid inside the chloroplast 3. Granum • Stacks of thylakoids 4. Thylakoids • Flattened sac-like structures inside the chloroplast 5. Lumen • Inner part of the thylakoid where a proton gradient is built up for ATP synthesis

A better look…

Photosynthesis Overview t gh Li O 2 CO 2 ADP + P Light dependent rxn’s in thylakoids Calvin Cycle (Carbon Fix. ) ATP Glucose H 2 O C 6 H 12 O 6

A. Solar Radiation - Solar radiation is described in terms of its wavelength. -Photons are discrete packets of radiant energy that travel in waves. 1. Visible Light: The portion of the electromagnetic spectrum as shown here: (380 nm – 740 nm: commonly rounded 400 -700 nm)

ROY G BIV (Light spectrum from longest to shortest wavelength) Longest wavelength Shortest wavelength

How Rainbows work: • In general shorter wavelengths (i. e. light towards the blue end of the spectrum) have higher indices of refraction and get bent more than light with longer wavelengths (towards the red end).

How Rainbows work: (cont. ) • Sunlight is often called white light, since it is a combination of all the visible colors. Since the index of refraction is different for each color, the angle of refraction will be different for each color when the light passes from air into glass, water (like raindrops) or other transparent material. This is according to Snell's Law.

Only 42% of solar radiation that hits earth’s atmosphere reaches surface, most as visible light. Higher energy wavelengths, like _______ are screened out by ozone layer in upper atmosphere. Lower energy wavelengths, like _______ are screened out by water vapor and carbon dioxide. (remember, energy content of photons is inversely proportional to wavelength)

Light may be: transmitted (passed through matter) reflected (bounced) or absorbed ( & subsequently changed from light energy to another form)

The matter of interest in the case of photosynthesis is the photosynthetic pigments, (the chlorophylls, and to a lesser extent, the carotenoids. ) PHOTONS of specific wavelengths are absorbed by molecules of plant pigments (a substance that absorbs light) chlorophyll a "team captain" chlorophyll b accessory (antenna) pigments carotenoids accessory (antenna) pigments

a CHLOROPHYLL a

The Light Reactions Overview: t gh Li O 2 The light CO 2 reactions: Chloroplast • Utilize the hydrogen from H 2 O to create a proton gradient inside Calvin Cycle (light the independent rxn’s) thylakoids, and release the CARBON oxygen as. FIXATION a waste product. Light dependent rxn’s in thylakoids ATP H 2 O • Happen in the thylakoids of the chloroplasts • The proton gradient inside thylakoids is used to make ATP via an Electron Transport Chain system. glucose

Chlorophyll a is a green pigment that absorbs red and blue-violet light [reflecting light-blue, green, & yellow light]. t a h t Chlorophyll b (alsoiar n e o h s green pigment) absorbs t a e : s wavelengths in thetblue and r n e nof the t e e red-orange parts e h r t h g m g g spectrum. [reflecting green s i i e ! l u p t r h s n l l e T ts a hlight] e y r e r n e p g a o h l All photoautotrophs containpcarotenoids, which absorb blue-violet r t e o h g t and blue-green wavelengths c that by theichlorophylls. hlare missed n b ctorange, They reflect wavelengths which arele red, and yellow. r o s f b e r ea il h w

These carotenoids are less abundant than chlorophylls in green leaves. However, they become more visible in autumn because plants stop producing chlorophyll as they prepare for the winter Thus the reason leaves change color! Tannins are waste products of cell processes found in vacuoles and cell walls, giving brown colorations. Anthocyanins are pigments generally produced in the fall from sugars and are responsible for pink to purple colors.

II. CHLOROPLAST Light travels as packets of energy called photons and is absorbed in this form by lightabsorbing chlorophyll molecules embedded in the thylakoid disks. DURING THE LIGHT DEPENDENT RXN

Stroma Lumen

Light

Light-Dependent Reactions • Occur across the thylakoid membranes • Requires photosystems made up of light absorbing pigments & an e- acceptor (P. E. A. ) • Only have ONE chlorophyll a per photosystem, though they contain hundreds or even thousands of antennae pigments • Only Chlorophyll a is capable of transferring the high energy electrons to the P. E. A.

Photosystem I and II • Photosystem I - chlorophyll a maximum absorbance at 700 nm Photosystem II - chlorophyll a maximum absorbance at 680 nm

IV. Light Independent Reaction • The chemical energy stored in the highenergy bonds of ATP and NADPH are harvested in the STROMA of the chloroplast. . where the Calvin Cycle reactions take place.

Photosynthesis Overview t gh Li O 2 CO 2 ADP + P Light dependent rxn’s in thylakoids Calvin Cycle (Carbon Fix. ) ATP Glucose H 2 O C 6 H 12 O 6

The Dark Reactions: Light Independent Rxns: CO 2 • Also called “Calvin Cycle” • Happens in the stroma (fluid inside the chloroplasts) ADP + P Light • Takes dependent ATP from the Light rxn’s in Dependent rxn’s and CO 2 thylakoids from the air & makes sugar out of it by utilizing the enzyme Rubisco (Ru. BP) • Sends ADP&P back to the Light Rxn’s to be “reloaded” for use again. Calvin Cycle (Carbon Fix. ) ATP Energy Glucose C 6 H 12 O 6

A quick note on Rubisco: The enzyme Rubisco is utilized to fix carbon in the Calvin Cycle. The actual name of this important enzyme is Ribulose-1, 5 -bisphosphate carboxylase. It is often abbreviated as Ru. BP or “Rubisco” for Light obvious reasons. dependent rxn’s in thylakoids Arguably the most important enzyme on earth because without it CO 2 couldn’t be made into sugar, and the entire food chain (& carbon cycle) would collapse! CO 2 Calvin Cycle (Carbon Fix. ) Glucose C 6 H 12 O 6

Photosynthesis Overview t gh Li O 2 CO 2 ADP + P Light dependent rxn’s in thylakoids Calvin Cycle (Carbon Fix. ) ATP Glucose H 2 O C 6 H 12 O 6

Photosynthesis Overview: