Cellular FunctionsMs. Durnford, Winter 2013

• Chapter 1– The Cell Theory– Cell Structure– Organelles– Animal and Plant Cells

• Chapter 2– Nutrients– Nucleic Acids– Cell Membrane– Transport– Respiration and Photosynthesis

2Biology 11

• Biology is a natural science concerned with the study of life and living organisms, including their:– Structure, – Function, – Growth,– Evolution,– Distribution and – Taxonomy

3Biology 11

• Biology as a Science progressed by observation.

• The hypotheses proposed by early scientists were rarely tested by experiments.

Biology as a Science progressed by observation!

4Biology 11

• Abiogenesis is the belief that living organisms can be created, or arise, from non living matter.

• Many abiogenesis hypothesis proposed by scientists were rarely tested by experiments.

• For Example:– Pond dries up – no fish or frogs– Rain comes – fish and frogs

Therefore: It rained fish and frogs

5Biology 11

• Proposed by Aristotle who observed rotting meat and flies.

• People Believed this for 2000 years!

6Biology 11

• Biogenesis is the principle that living organisms develop from other living organisms and not from non living matter.

7Biology 11

• There were a number of important Scientists who contributed to the theory of Abiogenesis and Biogenesis. Some of these include:

– Jean Van Helmont– Francesco Redi– John Needham– Lazzaro Spallanzani– Louis Pasteur

8Biology 11

• ~300 years ago

Belgian doctor Jean van Helmont – concluded that mice could be created from a dirty shirt.

• He placed grains of wheat and a dirty shirt in a container and in 21 days mice appeared.

• Conclusion: Sweat caused wheat to ferment into mice. Abiogenesis!

9Biology 11

• In 1668 Francesco Redi (Italian physician) tested Aristotle’s hypothesis (meat flies)

10Biology 11

11Biology 11

• 4 sets of jars with meat (snake, eel, fish, veal)

one set was open (experimental group)

one set was sealed (control group)

• Maggots appeared on open jars of meat

• Conclusion: Flies come from flies!

• Biogenesis – life from life.

12Biology 11

• John Needham (1713 – 1781) English botanist

• Reexamined theory of Abiogenesis

• Observed meat broth left unsealed soon changed colour (evidence of microorganisms).

13Biology 11

Experiment:

• Boiled flasks of meat broth to kill microorganisms

• Left the flasks (unsealed)

• Flasks soon become murky and full of microbes

14Biology 11

Conclusion:

• Abiogenesis

• This conclusion sent many scientists down the wrong path.

15Biology 11

• 25 years later Spallanzani repeated experiment more carefully

• Boiled flasks longer and sealed flasks

• Critics again objected to sealed flasks!

16Biology 11

• Louis Pasteur (1822-1895)

• Developed the swan neck flask in 1864

• This led to great scientific break through!

17Biology 11

18Biology 11

Experiment:

• Boiled broth, air could enter but microbes were trapped in curved flask

• Broth remained clear Biogenesis finally proven!

19Biology 11

Unit 1 Chapter 1

Biology 11 20

• All living things are composed of one or more cells.

• The cell is the basic unit of structure and function of all living things.

• All cells arise only from pre-existing cells.

Biology 11 21

• What is a prokaryotic cell?

– Prokaryotes and unicellular organisms that lack a nucleus and membrane bound organelles.

– These are the most simple types of living cells.

– Examples: cyanobacteria, E.Coli, thermoacidophiles

Biology 11 22

Biology 11 23

• Eukaryote cells do have a nucleus and membrane bound organelles.

• Eukaryotes can be multicellular– organisms made of many cells

OR

• Eukaryotes can be unicellular– organisms made only of one cell

• Plants, Animals, Fungus and Protists are all eukaryotes.

Biology 11 24

Biology 11 25

Biology 11 26

• Within cells there is an intricate network of organelles that all have unique functions.

• These organelles allow the cell to function properly.

• Here is a description of common organelles and their location.

Biology 11 27

• Nucleus– One or more per cell– Spherical shape– Denser than surrounding cytoplasm

• Chromosome– Usually in the form of chromatin– Contains genetic information– Composed of DNA– Thicken for cellular division– Set number per species (i.e. 23 pairs for human)

Biology 11 28

• Nuclear membrane– Surrounds nucleus– Composed of two layers– Numerous openings for nuclear traffic

• Nucleolus– Spherical shape– Visible when cell is not dividing– Contains RNA for protein manufacture

Biology 11 29

Biology 11 30

• Cytoplasm– Collective term for cytosol and organelles contained within– Colloidal suspension– Cytosol mainly composed of water with free-floating

molecules– Viscosity constantly changes

• Centrioles– Paired cylindrical organelles near nucleus– Composed of nine tubes, each with three tubules– Involved in cellular division– Lie at right angles to each other

Biology 11 31

• Chloroplasts– A plastid usually found in plant cells– Contain green chlorophyll where

photosynthesis takes place

• Cytoskeleton– Composed of microtubules– Supports cell and provides shape– Aids movement of materials in and out of cells

Biology 11 32

• Endoplasmic reticulum– Tubular network fused to nuclear membrane

– Goes through cytoplasm onto cell membrane

– Stores, separates, and serves as cell's transport system

– Smooth type: lacks ribosomes

– Rough type (pictured): ribosomes embedded in surface

• Golgi Apparatus– Protein 'packaging plant‘

– A membrane structure found near nucleus

– Composed of numerous layers forming a sac

Biology 11 33

Biology 11 34

Biology 11 35

• Mitochondira– Second largest organelle with

unique genetic structure– Double-layered outer membrane with inner folds

called cristae– Energy-producing chemical reactions take place on

cristae– Controls level of water and other materials in cell– Recycles and decomposes proteins, fats, and

carbohydrates, and forms urea

Biology 11 36

• Lysosome– Digestive 'plant' for proteins, lipids, and carbohydrates– Transports undigested material to cell membrane for removal– Vary in shape depending on process being carried out– Cell breaks down if lysosome explodes

• Ribosomes– Each cell contains thousands– Miniature 'protein factories‘– Composes 25% of cell's mass– Stationary type: embedded in rough endoplasmic reticulum– Mobile type: injects proteins directly into cytoplasm

Biology 11 37

• Vacuoles– Membrane-bound sacs for storage, digestion,

and waste removal– Contains water solution– Contractile vacuoles for water removal (in

unicellular organisms)

Biology 11 38

• Cell Wall– Most commonly found in plant cells– Controls turgity– Extracellular structure surrounding plasma membrane– Primary cell wall: extremely elastic– Secondary cell wall: forms around primary cell wall after

growth is complete

• Plasma membrane– Outer membrane of cell that controls cellular traffic– Contains proteins (left, gray) that span through the membrane

and allow passage of materials– Proteins are surrounded by a phospholipid bi-layer.

Biology 11 39

Biology 11 40

Plant Cells Animal Cells

Have chloroplasts and cell Walls

Do Not have chloroplasts and cell

walls

Do not usually have centrioles

Have centrioles

Have a large central vacuole

Do Not have a large central vacuole

Biology 11 41

Biology 11 42

Biology 11 43

• Cell Theory Article

• Video

• Questions

• For Extra Practice on the cell visit QUIZLET

Biology 11 44

Unit 2

Biology 11 45

• Organic compounds are Carbon (C) based compounds.

• The three elements we will be looking at are:– Hydrogen– Oxygen– Carbon

Biology 11 46

• Is the building of a larger, more complex compound by the removal of a water molecule from two smaller, less complex compounds. (an anabolic process)

A + B AB + H2O

Biology 11 47

• Dehydration Synthesis

Biology 11 48

• The reverse process of dehydration synthesis.

• The breaking down of a larger more complex compound into two smaller less complex compounds by the addition of a water molecule. (a catabolic process)

AB + H2O A + B

Biology 11 49

• Living things (including cells) are composed of the following types of organic compounds:– Carbohydrates– Lipids– Proteins– Nucleic acids

Carbohydrates

• What are they?– You get carbohydrates from fruits, grains etc.– The building blocks of carbohydrates are

monosaccarides– Quick chemical energy– Can be used for structure (ie; Cell Wall)

Examples• Starch, fructose, sucrose, cellulose

• Sugars and starches

• Used for energy (example = glucose) and structural parts of cells (example = cellulose)

• Contain the following elements: C, H & O

• Always have a 2:1 ratio of H:O

Biology 11 52

Key Terms

• Monomer

• Polymer

• There are three types of carbohydrates:– Monosaccharides

– Disaccharides

– Polysaccharides

Biology 11 54

• Building blocks = monosaccharides

examples: glucose, fructose, galactose

• Monosaccharides are also known as single sugars.

• Molecular formula = C6H12O6

Biology 11 55

• Structural formula for glucose:

Biology 11 56

• Disaccharides are double sugars.

• Molecular formula = C12H22O11

• Examples:– Maltose = glucose + glucose– Lactose = glucose + galactose– Sucrose = glucose + fructose

Notice the “ose” trend???

Biology 11 57

• Polysaccharides are complex carbohydrates

• Examples = cellulose, starch, glycogen and chitin

Biology 11 58

• a polysaccharide that is the principal  component of the exoskeletons of  arthropods and of the bodies of fungi.

• Exoskeletons are made of chitin.

Biology 11 59

Questions1. What is an organic compound?

2. Compare and contrast dehydration synthesis and hydrolysis.

3. What is the difference between monosaccharides, disaccharides, and polysaccharides?

4. a) Give some examples of complex carbohydrates.

b) How could a cell get usable energy from starch or glycogen?

Text book starting on page 32

• Contain elements C, H & O

• Do not dissolve in water!

• Supply energy to the cells of the body, but difficult for the body to break down.

Biology 11 61

• Long term energy storage– 1g of lipid contains 2.25 X as much energy as

1g of carbohydrate!

• Cushioning of internal organs

• Hormones (estrogens, testosterone)

• Absorption of vitamins.

• Cell membrane (phospholipids)

Biology 11 62

Lipids

Three groups:

• fats, oils, and waxes

• phospholipids

• steroids

Lipids

• Large molecules composed of two types of monomers

• Glycerol – three carbon molecule containing three hydroxyl groups

• Fatty Acids – chains of carbon and hydrogen, ended with a carboxyl group

Lipids

Fats, Oils, Waxes

• Include: – Triglycerides– Saturated Fats– Unsaturated Fats

Lipids

Triglycerides

• Most common type of lipid.

• Energy storing.

• 1 glycerol and 3 fatty acids.

Biology 11 67

Fats, or triglycerides, are formed by the union of glycerol and three fatty acids.

• Fatty acid contains only carbon-carbon single bonds with max number of hydrogen atoms.

• The greater the number of hydrogen atoms, the firmer the fat.

• Examples: lard and butter, animal fats.

Biology 11 68

• Fatty acid in which there is at least one double bond within the fatty acid chain and has some hydrogen missing.

• More easily broken down than saturated fats.

• Examples: sunflower seed oil, plant fats, fish fats.

Biology 11 69

Lipids

Phospholipids

• Main components of cell membranes.

• Made of a phosphate group and two fatty acids.

• Polar end – hydrophilic – soluble in water.

• Non-polar end – hydrophobic – insoluble.

• What are the three groups of lipids?

• What are the monomers of lipids?

• Why are saturated fats harder to break down than unsaturated fats?

Biology 11 72

Proteins

• Proteins contain elements C, H, O & N (nitrogen!)

• They are used by cells to build structures and are used in chemical activities.

Proteins

• Examples: – Feathers, wool, silk– hormones (example = insulin)– Hemoglobin– Enzymes– membrane proteins– Hair, muscles, nails (example = collagen).

Proteins

• Proteins are associated with building cell structures. Whenever cells are damaged and require repair, proteins are manufactured.

• Proteins are composed of 20 different amino acid building blocks.

• There are 8 amino acids that the body cannot make! These essential amino acids must be obtain through food.

• Building blocks of proteins = Amino Acids

• General formula:

• R= Variable. This differs for each of the 20 Amino Acids

Biology 11 76

Proteins

Polypeptide

• a long chain of amino acids

• a bond formed between amino acids is a peptide bond.

• a protein is composed of one or more polypeptides

• insulin is the smallest polypeptide (51)

Proteins

• Structure:

• A unique sequence of amino acids.

• The chain bends and folds.

• The shape is important to its function.

• How would you be able to identify a carbohydrate, from a lipid, from a protein?

• Compare and contrast:– carbohydrate & lipid– lipid & protein– carbohydrate & protein

Biology 11 79

• What are the building blocks of carbohydrates, give an example.

• How / where are polypeptides built?

• List two functions of lipids.

• What are the components of a triglyceride?

Biology 11 80

Read pgs. 32-42 to assist in answering questions.

• The two nucleic acids, DNA and RNA, are not nutrients but they are essential for all living things.

Biology 11 81

• DNA (deoxyribonucleic acid) is the genetic code for almost every living organism

• DNA is often called a double helix because of the way it coils

Biology 11 82

• The sugar and the phosphate molecules form the backbone of the spiral ladder, while the nitrogenous bases form the rungs.

• Nitrogenous bases from one side of the “ladder” are paired with nitrogenous bases.

Biology 11 83

•There are 4 bases to DNA called nucleotides: A (adenine) T (thymine) C (cytosine) G (guanine)

Biology 11 84

• Adenine and guanine always combine together.

• Cytosine and thymine combine together.

Biology 11 85

• Ribonucleic acid.

• RNA transmits genetic information from DNA to proteins produced by the cell.

• Unlike DNA, RNA is single-stranded. An RNA strand has a backbone made of alternating sugar (ribose) and phosphate groups. 

Biology 11 86

• RNA also has 4 nucleotides:

A (adenine) U (uracil) C (cytosine) G (guanine)

Biology 11 87

• Organic Compound review Sheet

Biology 11 88

Cell MembraneBiology 11

• The living cell has to maintain an internal balance. (homeostasis)

• The plasma membrane is selectively permeable – it allows some substances to cross membrane, but blocks others.

Biology 11 90

Biology 11 91

The fluid-mosaic model describes the plasma membrane of animal cells.

The plasma membrane that surrounds these cells has two layers (a bilayer) of phospholipids (fats with phosphorous attached), which at body temperature are like vegetable oil (fluid).

• Each phospholipid molecule has a head that is attracted to water (hydrophilic: hydro = water; philic = loving) and a tail that repels water (hydrophobic: hydro = water; phobic = fearing).

• Both layers of the plasma membrane have the hydrophilic heads pointing toward the outside; the hydrophobic tails form the inside of the bilayer.

Biology 11 92

• Because cells reside in a watery solution (extracellular fluid), and they contain a watery solution inside of them (cytoplasm), the plasma membrane forms a circle around each cell so that the water-loving heads are in contact with the fluid, and the water-fearing tails are protected on the inside.

Biology 11 93

• There are no chemical bonds between the phospholipid molecules – they are free to move around laterally.

• Proteins are found throughout the plasma membrane that can also move around, like icebergs in a sea of phospholipids

Biology 11 94

• Carbohydrates can also be attached to the outer surface of the plasma membrane.

– Carb. attached to a phospholipid = glycolipid

– Carb. attached to a protein = glycoprotein

Biology 11 95

• Proteins and substances such as cholesterol become embedded in the bilayer, giving the membrane the look of a mosaic.

• Because the plasma membrane has the consistency of vegetable oil at body temperature, the proteins and other substances are able to move across it.

Biology 11 96

• The molecules that are embedded in the plasma membrane also serve a purpose.

• For example, the cholesterol that is stuck in there makes the membrane more stable and prevents it from solidifying when your body temperature is low.

Biology 11 97

Biology 11 98

Biology 11 99

• Cell Membrane Tutorial

Biology 11 100

Cell Transport

Biology 11

• Two parts of a Solution:

–Solute• A substance dissolved in another substance,

usually in lesser amount.

–Solvent• A substance in which another substance is

dissolved, forming a solution

Biology 11 102

• Cell membranes are selectively permeable. This means that some things can pas through while others cannot.

• Proteins embedded in the cell membrane are used as channels and pumps which allow substances through or not.

Biology 11 103

Cell TransportCell Transport

Diffusion• Diffusion is the movement of molecules from an

area of high concentration to an area of lower concentration.

Cell Transport

• There are three types of cell transport:

– Simple Diffusion

– Facilitated Diffusion

– Active Transport

Passive Transport

• Passive Transport: Movement of materials across the cell membrane going with the concentration gradient (from a region of greater concentration to a region of lesser concentration).

Simple Diffusion and Facilitated Diffusion are both examples of Passive Transport

• *Cell uses no energy to transport particles!

Simple Diffusion

• No transport protein used

• Movement with the concentration gradient (high to low)

• No additional cell energy required

• Examples: water, oxygen, carbon dioxide.

Homeostasis

• To maintain a stable, constant condition.

• To maintain equilibrium.

• The cell wants its internal environment to be the same as its external environment.

Concentration Gradient

• When there is a difference in concentrations:– High concentration means more particles– Low concentration means less particles

– In diffusion, particles move from a high concentration to a low concentration to reach on EQUAL concentration (equilibrium) on each side.

Passive Transport Examples

• a) Osmosis – specific type of diffusion (can you remember the definition??)

• b) Facilitated diffusion – Process by which molecules diffuse across a cell membrane with the aid of transport proteins. This is for particles that cannot dissolve into the lipid bi-layer or are too large to pass through.

PassiveTransport

• A solution that has the same concentration of solutes as the cell.

• Therefore there is no net movement of water molecules

Biology 11 112

Hypertonic

• The solution has higher concentration of solutes then the cell.

• Therefore there will be a net movement OUT of the cell.

• A solution that has a lower concentration of solutes than the cell.

• There will be a net movement of water into the cell.

Biology 11 114

Hypotonic

Osmotic Pressure

• This is the pressure that water exerts on the hypertonic side of a selectively permeably membrane.

• It can be problematic for living cells because they can burst from over-inflation with water or shrivel up from loss of water.

Biology 11 116

Cytolysis: The bursting or rupture of a cell.

Biology 11 117

Facilitated Diffusion

• Transport protein used: carrier protein or channel protein

• Movement with the concentration gradient

• No additional cell energy required

• Passive

• Example: glucose molecules

Facilitated Diffusion

• Similar to simple diffusion in the sense that it is diffusion (across a membrane) from a high concentration to a lower concentration.

• However, this time the rate of diffusion is greatly accelerated by the action of membrane proteins that act as carrier molecules and aid in diffusion.

Facilitated Diffusion

Protein Channels Carrier Proteins

• Passive Transport Video

Active Transport

• Molecular Active Transport: Movement of materials across the cell membrane going against the concentration gradient (from a region of lesser concentration to a region of greater concentration).

• *Requires energy from cell!

Active Transport

• Transport protein used: Carrier Protein

• Movement AGAINST the concentration gradient (low to high)

• Additional cell energy required

• Active

• Example:

Sodium Potassium Pump

Active Transport

• Molecular active transport involves protein pumps.

• Examples of active transport:– Cells in Gills of marine fish actively pump out

salts.– Root cells of plants often take in large

quantities of ions.

• Active transport Video

Sodium Potassium PumpActive Transport

Bulk Membrane Transport

• Active transport (requires energy)

• Requires the creation of vacuoles and vesicles

• Two types:– Endocytosis– Exocytosis

Animation

Endocytosis• Endocytosis: The process by which the plasma

membrane engulfs and takes in substances from a cell’s environment. *Common in unicellular organisms.

• 2 types:– i) Phagocytosis: Form of endocytosis in which large

solid particles are taken into the cell. Example – WBC’s engulfing harmful bacteria

– ii) Pinocytosis: Form of endocytosis in which small liquid droplets are taken into the cell. a.k.a. cell drinking

Endocytosis

Phagocytosis

Exocytosis

• Exocytosis: Cell products or wastes are enclosed in vesicles and released to outside of cell.

• Process:– Golgi Apparatus “packages” the material into a vesicle and

sends it to the cell membrane– The vesicle fuses with the membrane– The material is deposited outside the cell

*Reverse process of endocytosis.

• Examples = secretion or elimination of waste

Energy and Life

Photosynthesis and Respiration

Biology 11 133

What is energy?• Energy is the capacity to do work.

• All living this require energy, but how do they get it?

• There are two ways to receive energy,– Produce it– Consume it

Photosynthesis

• The sun is the main source of energy for the earth.

• Autotrophs make their own food, and most are green plants.

• This is done through the process of Photosynthesis.

Photosynthesis

• We know photosynthesis requires energy from the sun, but the sun is not available 24 hours a day!

• Photosynthesis must occur in two phases:– Light dependent reactions

• Convert light energy into chemical energy (ATP and NADPH)

– Light independent reactions• Uses ATP and NADPH from the light dependent

reactions to build glucose.

Role of Photosynthesis• Plants use it to make food

• Animals get their food from plants, so therefore, from photosynthesis as well (consumers)

• Photosynthesis also produces oxygen which most living things need to respire and live.

The process of photosynthesis

• Light is trapped by chlorophyll and provides energy for photosynthesis

• Sunlight energy is used to split water in half (photolysis)

The process of photosynthesis

• Products from splitting water:– Protons stored for later use– Electrons Passed to chorophyll– Oxygen can be used in respiration or

release

• Light energized the electrons and turns them into high energy electrons. These are passed down an electron transport chain

Electron Transport Chain

• Is a series of proteins on the thylakoid membrane of chloroplasts.

• Electrons are passed from one protein to another, and energy is released which:– Helps join ADP and phosphate to form ATP– Allows hydrogen to join with NADP to form

NADPH– Both forms of energy are used in light

independent reactions.

Process of Photosynthesis

• Glucose is formed when the high energy electrons, protons from storage and carbon dioxide from air are combined.

• This is takes place in chloroplasts and is known as the Calvin Cycle. This is a part of the light independent reactions.

The Calvin Cycle• 1. Grab: A five-carbon carbon catcher catches

one molecule of carbon dioxide and forms a six-carbon molecule.

• 2. Split: the enzyme RuBisCO (with the energy of ATP and NADPH molecules) breaks the six-carbon molecule into two equal parts.

• NADP (nicotinamide adenine dinucleotide phosphate) is a coenzyme that carries electrical energy used in cellular processes.

The Calvin Cycle• 3. Leave: A trio of three carbons leave and

become sugar. The other trio moves on to the next step.

• 4. Switch: Using ATP and NADPH, the three carbon molecule is changed into a five carbon molecule.

• 5. The cycle starts over again

Photosynthesis• Once sugars are created through the calvin cycle,

mitochondria can now use it for cellular respiration.

• The mitochondria uses glucose, or sugars, to create ATP which is a usable energy for the cell.

• This not only occurs in plant cells, but in our own cells as well. By consuming other plants and animals, our body uses the sugars ( carbohydrates) that we eat into usable energy by mitochondra.

Review Questions

• What is the primary function of photosynthesis?

• Name two molecules that are produced during the light dependent reactions of photosynthesis and serve as temporary sites for energy storage.

• In eukaryotic cells, photosynthesis occurs in organelles named?

• True or False The Calvin cycle (= light-independent reactions) can occur in a plant that is in dark room so long as the materials carbon dioxide, ATP, and NADP-H are present.

Cellular Respiration

• Process by which mitochondria break down food molecules to produce ATP in plants and animals.

• Nutrients + Oxygen Water + ATP + CO2

Cellular respiration

• Changes organic chemical energy (glucose) into inorganic chemical energy (ATP)

• Three stages of cellular respiration– Glycolosis

• Anaerobic ( does not require oxygen)

– Krebs Cycle• Aerobic ( requires oxygen)

– Electron Transport Chain• Aerobic (requires oxygen)

Glycolysis

• Breaks down glucose into two molecules of pyruvic acid

• Uses enzymes and takes place in the cytoplasm of the cell

• Produces– 2 pyruvic acid molecules – used in next step

of cellular respiration– 2 ATP molecules –energy for the cell– 2 NADH – electron carrier

• Before the next step of cellular respiration, the pyruvic acid molecules formed in the glycolysis must go into the mitochondria.

• The next two aerobic reactions will then form:

Pyruvic acid CO2 + Water + ATP

Krebs Cycle

• Is a series of chemical reactions used by all aerobic organisms to generate energy.

• Provides the hydrogen and electrons needed for the electron transport chain, which happens in the mitochondria.

Krebs Cycle

• The following is formed during the Krebs Cycle:

– 2 Molecules of CO2 are released– 2 Molecules of ATP are formed– 3 molecules of NAD+ are combined with

hydrogen ( NAD+ NADH)– 1 molecule of FAD+ combines with hydrogen

( FAD+ FADH)

Electron Transport Chain

• Following the Krebs cycle, the electron transport chain uses the electron carriers (NADH and FADH2) to pass electrons down a protein chain and slowly releases energy that is used to form ATP and water molecules.

• This transfers the most energy.

Equation

Summary

• Photosynthesis- Converts solar energy into chemical energy

• Cellular Respiration – Converts chemical energy into usable energy

• Therefore living things deal with three types of energy!– Solar energy– Chemical energy (sugars / lipids)– Usable energy (A.T.P.)

Review Questions• What are the three main processes of Cellular

Respiration?

• What is produced during glycolysis?

• Name two electron carriers.

• Compare and contrast:– Anaerobic and aerobic– Photosynthesis and Cellular respiration