Cell Respiration:Stage 1: Food Breakdown

Before food can be processed into ATP, large polymeric molecules must be broken down into their basic units. For example, proteins must be broken down into amino acids and polysaccharides must be broken down into glucose. This step is known as digestion. Most of digestion takes place in the digestive tract of animals and food is broken down by secreted enzymes. 

Even after all of the molecules have been broken down into their basic units, most of the non-glucose molecules are subsequently converted into glycose so that they can be processed during glycolysis. The following table lists the food molecules and there basic unit.

Complex Food Molecule Basic Units Proteins Amino Acids Polysaccharides Simple Sugars (e.g. glucose) Fats (Lipids) Fatty Acids and Glycerol

Cell Respiration

Process that releases energy (chemical) by breaking down glucose and other food molecules in the presence of oxygen

Occurs in both plants and animals and fungi

There are 2 types

Aerobic RespirationAnaerobic Respiration- With OXYGEN

- Without OXYGEN

The whole process is divided into 2 parts: Anaerobic

No Oxygen Occurs in cytoplasm Glycolysis is an

anaerobic process Glucose is broken

into pyruvic acid and ATP

Aerobic Oxygen Occurs in

mitochondria Divided into 2

stages: Kreb cycle (citric acid

cycle) Electron Transport

Chain

Glycolysis

Remember…”-lysis” means “to break”

Glucose is broken down into 2 molecules of PYRUVATE

Glycolysis is anaerobic Pyruvate can then be used for

cellular respiration Location: cytoplasm Occurs before cellular respiration can

happen

Glycolysis

Once glucose is imported into the cell: Glucose is broken down into 2 molecules

of pyruvate Produces 4 ATP per glucose 2 ATP molecules are “used” up leaving us

with a net gain of 2 ATP molecules produced for the cell to use for energy.

Pyruvate enters the mitochondria and provides the materials needed for the Kreb’s cycle

http://highered.mcgraw-hill.com/sites/0072507470/student_view0/chapter25/animation__how_glycolysis_works.html

GlucoseGlycolysi

s

Electrons carried in NADH

Pyruvic acid

Krebs

Cycle

Electron Transport

Chain

Electrons

carried in NADH

and FADH2

CytoplasmMitochondrion

Aerobic Respiration

Requires Oxygen More effective than anaerobic

(without oxygen), make MUCH MORE ATP

Location: Mitochondria

Aerobic Respiration

KNOW THE FORMULA!!!

C6H12O6 + 6O2 6H2O + 6CO2 + ATP

GLUCOSE (FOOD) OXYGEN WATER CARBON DIOXIDE

Steps of the Process Glycolysis Krebs Cycle Electron Transport Chain (ETC)

Kreb’s Cycle (citric acid cycle) Breaks pyruvate down into CO2

Occurs in the mitochondria Produces 2 ATP per glucose Produces NADH & FADH2

FADH2 and NADH provide power for the ETC FADH2 and NADH are carrying chemical

energy The carbon dioxide produced here diffuses

out of the mitochondria, out of the cell and into the bloodstream where it is carried to the lungs and diffuses into the air that we exhale.

http://highered.mcgraw-hill.com/sites/0072507470/student_view0/chapter25/animation__how_the_krebs_cycle_works__quiz_1_.html

Electron Transport Chain(ETC)

Occurs in the lining of the mitochondrial membrane FADH2 and NADH pass some of their electrons onto

the ETC ETC is like a game of hot potato, where electrons

from FADH2 and NADH are the potato, and proteins in the mitochondria are the people passing the potato. OXYGEN IS REQUIRED. The flow of electrons down the chain powers a

special protein, called “ATP synthase,” which synthesizes (makes) ATP

Produces 32 ATP per glucose! Total ATP production per glucose during

aerobic respiration = 36 ATP

http://highered.mcgraw-hill.com/sites/0072507470/student_view0/chapter25/animation__electron_transport_system_and_atp_synthesis__quiz_1_.html

ATP Production

Electron TransportHydrogen Ion Movement

Channel

ATP synthase

Intermembrane Space

Inner Membran

e

Matrix

Anaerobic Respiration:Fermentation

Sometimes a cell can’t get the oxygen that it needs to carry out aerobic respiration.

It carries out fermentation to make energy instead (ATP)

Less EFFECTIVE, doesn’t make as much ATP

Location: Cytoplasm

Fermentation

Isn’t a “clean burn” so nasty, or intoxicating, waste products are left behind There are 2 types

Alcoholic Fermentation

-Produces ethanol (alcohol) as a waste product

-Used for producing beer, wine, and rising bread

Lactic Acid Fermentation

Produces lactic acid as a waste product

-Is part of the burn you feel in your muscles when you exercise.

Lactic Acid Fermentation

•Notice that a total of 2 ATP molecules are made for each molecule of glucose during glycolysis

•Notice that NAD+ is “regenerated” to be used in glycolysis•This is a low energy yield process (only 2 ATP’s) but this can be enough to sustain our cells when we can’t get enough oxygen

Alcoholic Fermentation

alcoholic fermentation, is a biological process in which sugars such as glucose, fructose, and sucrose are converted into cellular energy and thereby produce ethanol and carbon dioxide as metabolic waste products. Because yeasts perform this process in the absence of oxygen, ethanol fermentation is classified as anaerobic. Ethanol fermentation occurs in the production of alcoholic beverages and ethanol fuel, and in the rising of bread dough.

C6H12O6 → 2C2H5OH + 2CO2

(ethanol)

*** 2 ATP molecules are made. NAD+ is reused in Glycolysi

Prokaryotic vs Eukaryotic Prokaryotic: Remember has no nucleus or no

membranes around their organelles. So where does Aerobic Respiration occur here?

Prokaryotic Cells Eukaryotic Cells Glycolysis: Cytoplasm Glycolysis:

Cytoplasm Krebs Cycle: Cytoplasm Krebs Cycle:

Mitochondria ETC: Cell Membrane ETC:

Mitochondrial Membrane Fermentation: cytoplasm Ferm: Cytoplasm

Prokaryotic cells can yield a maximum of 38 ATP molecules while eukaryotic cells can yield a maximum of 36. In eukaryotic cells, the NADH molecules produced in glycolysis pass through the mitochondrial membrane, which "costs" two ATP moleculeshttp://biology.about.com/library/quiz/blcellresquiz.htm

Chemical formulas for Photosynthesis and Cell Respiration

Photosysthesis: 6CO2 + 6H2O + Light Energy = C6H12O6 +

6O2

Cell Respiration

C6H12O6 + 6O2 6H2O + 6CO2 + ATP

Products of PhotosynthesisO2 + C6H12O6

(Reactants of photosynthesis

CO2 + H2O + ATP)

Reactants of Respirations(products of respiration

CO2 + H2O + ATP)

Photosynthesis Light To Make

Photosynthesis is the process of converting light energy to chemical energy and storing it as sugar.

This process occurs in plants and some algae (Kingdom Protista).

Plants need only light energy, CO2, and H2O to make sugar.

The process of photosynthesis takes place in the chloroplasts, specifically using chlorophyll, the green pigment involved in photosynthesis.

Why does Chlorophyll have a green color? Chlorophyll absorbs red and blue wavelengths

of light. However, it can not absorb the green wavelengths of light very well. As a result, it reflects the green wavelengths, which when they hit our eyes, we perceive as the color green.

6CO2 + 6H2O + Light Energy = C6H12O6 + 6O2

Photosynthesis Step 1: Absorb light and break down H 2O into H+, H+,

and O.

a.The remaining O’s from the water join together to form O2

Step 2: Light Energy converted to ATP (Light reaction)

a. Occurs in the thylakoid membranes o f the cloroplasts Step 3: Dark Reaction (Calvin Cycle)

a. Occurs in the Stroma of the chloroplasts

The reactions of photosynthesis can be categorized as light-dependent reactions and dark reactions.

1. light dependent reactions The light dependent reaction

happens when solar energy is captured to make a

molecule called ATP (adenosine tri-

phosphate). 2. light independent or dark reactions.

The dark reaction happens when the ATP is used to make glucose (the Calvin Cycle).

Light Reactions: Making ATP and NADPH light dependent reactions The light dependent reaction

happens when solar energy is captured to make a molecule called ATP (adenosine tri-phosphate).

Thylakoid Membrane: Electron Transport Chain Light causes the movement of hydrogen ions through the

protein (enzyme) provides energy to make ATP (photosystem 2: blue )

Also provides energy to make NADPH (electron acceptor) (photosystem 1 )

Red

Oxygen is given off

Dark Reactions: Calvin Cycle light independent or dark reactions. The dark

reaction happens when the ATP and CO2 is used to make glucose (the Calvin Cycle).

6 CO2 are added to a five Carbon Compound sugar

P-C-C-C-C-C-P + CO2

ATP ADP, NADPH NADP+ These break down into Six 3 carbon sugars

(6) P-C-C-C One 3 carbon sugar is used to make Starch or

Sucrose The other 5 3carbon sugars are used to

regenerate the initial 5carbon compound

http://www.dnatube.com/video/2899/Photosynthesis-101-presented-by-Dr-Undergrad

What affects Photosynthesis? Amount of Light

- Rate of photosynthesis increases with more light

- one saturation is reached it will level off: Pigments

cannot absorb any more light. Amount of CO2

- Rate of photosynthesis increases with more CO2

- Saturation level reached cannot rate will level off Temperature

- Decreased temps will decrease rate

- WHY? Enzyme activity

Photosynthesis

Energy capture

Chloroplast

CO2 and H2O

C6H12O6 and O2

6CO2 + 6H2O C6H12O6 + 6O2

Cellular Respiration

Energy release

Mitochondria

C6H12O6 and O2

CO2 and H2O

6O2 + C6H12O6 6CO2 +

6 H2O

Function

Location

Reactants

Products

Equation