Lesson Overview2.3 Carbon Compounds

Organic and inorganic compoundsOrganic• Carbon-carbon bonds• With Hydrogen• LARGE, COMPLEX

– Ex. Nutrients• Made in living things

4 Main life molecules• Carbohydrates• Lipids (fats)• Nucleic acids (DNA)• proteins

Inorganic• Might have carbon, but NO

– Hydrogen– Carbon-carbon bonds– Ex. CO2 CaCO3

• Small, few atoms• Some are in living things

Inorganics needed for life:• Water• Minerals, salts

Vitamins are organic, need in small amounts

The Carbon AtomWhat makes carbon so special?

Atomic number _____ valence electrons ____How many bonds form? Carbon-carbon bonds big, complex structures

Carbon can make large molecules

Organic – compounds with at least one carbon atom, and always with hydrogen

Carbon can form large, complex structures• Carbon-carbon bonds• chains, branches, rings

Macromolecules

Are large molecules (macro) made of smaller units• Form by linking smaller molecules

(monomers) together in chains• polymer – long chain of monomers• Chemical process is polymerization• Chemical reaction is dehydration

synthesis (or condensation)• All organisms use the SAME

MONOMERS!!!

How do monomers link together?

DEHYDRATION SYNTHESIS (Condensation) reaction “Put together” by “removing water”

Cells synthesize large molecules by linking small molecules together

• Each link removes one water molecule** need enzymes, special molecules that help in all

chemical reactions in a cell**

LE 3-3a

Short polymer Unlinked monomer

Dehydrationreaction

Longer polymerNew bond formed

How do monomers link together?

How do large molecules break apart?

Hydrolysis reaction (Hydro – water; lysis = break)

1. ADD a water molecule – breaks a linking bond2. Water separates into H atom and OH group3. These atoms bond to the smaller molecules that form where the link breaks4. Result two separate smaller molecules

**Enzymes needed** • Ex. Lactose intolerance -- lactase enzyme does not break

down lactose sugar • Many enzyme names end in -ase

LE 3-3b

Hydrolysisreaction

How do large molecules break apart?

Breaks linking bond

Water molecule is added

CarbohydratesSUGARS, STARCHES, FIBER• Elements: CARBON, HYDROGEN, OXYGEN (2H : 1O)• Functions: mostly for ENERGY ; some for STRUCTURE

Monomer: SIMPLE SUGAR or MONOSACCHARIDE• Carbon chain with –OH groups• Can be chain or ring shape

- more stable as a ring • Ex. Glucose is a simple sugar

Monosaccharides• Some function alone• Some combine to make larger molecules• most common size: 5-6 carbons in chain

CARBS – MAIN SOURCE OF ENERGY FOR ALL ORGANISMS

GLUCOSE C6 H12 O6

• energy molecule for ALL organisms• Molecule used in cell respiration to make energy • Monomer for all complex carbs

STARCH is a large polymer made of glucose

Some shortcuts for drawing organic molecules

Isomers of glucoseC6H12O6 is also the formula for two other sugars,

FRUCTOSE and GALACTOSE– same atoms, but different sugar different structure

ISOMERS: molecules with the same formula but different shape– Different shape have different properties

**DON’T confuse isomer and isotope.

They are two different things!!

Important Monosaccharides

ISOMERS: All have the same molecular formula C6H12O6

but different structural formula1. glucose – #1 energy for all organisms

• Broken down for energy in cellular respiration• Building unit for all complex carbs, ex. starch

2. fructose – found in fruits, honey, syrup• Has the sweetest taste

3. galactose – part of lactose, the sugar in milk

Disaccharides – double sugars

Cells link two single sugars to form disaccharides• dehydration synthesis• For short-term stored energy

Animation: Disaccharides

Glucose Glucose

Maltose

Many carb names end in -ose

Important disaccharides• Sucrose: glucose + fructose

– “table sugar”– in plant sap– We get it from sugar beets and sugar cane

• Lactose: in milk

• Maltose : • In seeds, stored food for embryonic plant• Animals make it when they digest

complex carbs like starch

LE 3-7

Starch granules inpotato tuber cells

Glycogengranules inmuscletissues

Cellulose fibrils ina plant cell wall

Cellulosemolecules

GLYCOGEN

CELLULOSE

STARCHGlucose

monomer

Polysaccharides = complex carbs

• Polymers of glucose• Link by dehydration synthesis• Long-term stored energy, or structure

Storage polysaccharides

Starch – storage form of carbs in plants• Stored in seeds, roots, special cell parts• Foods: vegetables, fruits, grains

Glycogen – storage form of carbs in animals

• In liver and muscle cells• If glucose levels in blood drop, glycogen is changed into glucose

Starch granules

Structure polysaccharide- Cellulose

• structure and support in plants• in cell walls, wood, paper, cotton, fabrics• Strong and flexible: linked parallel chains

Cellulose makes plant cell walls

Lipids – fats, oils, and waxesElements: carbon, hydrogen, oxygen (less O than in carbs)Functions: stores concentrated energy

– Long-term storage– 9 cal/g

• more than 2X calories of carbs (4 cal/g)

Nonpolar (no +/- areas) do NOT dissolve in water hydrophobic – “stay away from water”

Other Lipids Functions1. Cell parts, especially membranes2. Waterproof coverings (ex. fruits, leaves, feathers)3. Some hormones (chemical messengers)4. Transport fat-soluble vitamins (needed in chemical

reactions)5. Insulates (stores heat); padding, 6. Protection – padding, especially around vital

organs7. Lubricates smooth movement in joints

Two lipid monomers

1) Glycerol - 3 carbon chain - each carbon has OH (hydroxyl group)

2) Fatty Acid - Hydrocarbon chain

- has carboxyl group on one end - COOH* C-H nonpolar covalent bonds

Lipid monomers join by dehydration synthesis

-OH group on each molecule is site for linking bond- Each link makes one water molecule

Triglyceride – common FAT molecule

One glycerol +

three fatty acids(3 dehydration reactions)

- makes 3 water molecules

Notice the double bond Molecule bends at this point

Make a triglyceride – dehydration synthesis

To Break Down a Fat

3 hydrolysis reactions• Uses 3 water molecules

Saturated and Unsaturated Fats

Saturated fatty acids – “saturated” with hydrogen atoms– All carbon-carbon bonds are single– Solid at room temp, mostly animal fats

• Except: coconut and palm oils– Health hazard increases cholesterol in blood

Unsaturated FatsHave one or more Unsaturated fatty acids

• One or more double bonds between carbons • Liquid at room temp, most plant oils, fish (omega- 3)• Healthier for humans – less cholesterol forms Monounsaturated Polyunsaturated

Saturated fats pack tightly solid at room temperature

Unsaturated fats pack loosely liquid at room temperature

What are “trans fats”?

1. Hydrogen is added to unsaturated fats a. “hydrogenated vegetable oil” b. Makes them more saturated

2. In processed foods, baked goods 3. For texture and taste, longer shelf life4. Can’t digest raises cholesterol - higher risk of heart disease, diabetes

Food labels list types of carbs and fats

Cholesterol and steroids -A different type of lipid

Carbon backbone is four joined carbon rings• various chemical groups attached to carbon rings

--> Causes different properties

cholesterol

Cholesterol – an important steroid

• Makes up part of animal cell membranes• Raw material for other molecules

– steroid hormones– cortisone and other anti-inflammatories

Other Steroid molecules

EstrogenTestosterone

All have backbone of 4 joined carbon rings

Inside a blood vessel -fatty plaque reduces space

WHERE DOES IT COME FROM? we make it in our liver we eat it in animal products

WHY IS TOO MUCH OF IT UNHEALTHY? If we eat more than we use, excess circulates in the blood Forms a soft, waxy substance called plaque ATHEROSCLEROSIS – fatty deposits inside blood vessels Clogs blood vessels – blocks flow of blood

Why is Cholesterol bad?

Heart Disease

Coronary arteries supply blood to heart muscle

Fatty plaques build up inside artery – decreases space for blood to flowTissues don’t get enough blood ” heart attack”

Angioplasty – a treatment for clogged blood vessels

Catheter inside artery, guided to site of blockage

Balloon inflated then removed;

mesh stent remains

Bypass surgery – detour around clogged blood vessels

Restores blood flow to heart muscle

Phospholipids and waxes

Phospholipids• Two fatty acids and phosphorus• Main component of cell membranes

Waxes • a single fatty acid linked to an alcohol• Form waterproof coatings

ProteinsElements: carbon, hydrogen, oxygen, nitrogen (sometimes sulfur)Monomer: amino acids3 parts: 1) amino group (NH2)

2) carboxyl group (COOH) 3) side chain (R group)

20 different R groups

Parts of an amino acid

20 different R groups - make 20 different amino acids

Making a protein polymer

Polymer: polypeptide - forms by linking amino acids

Uses dehydration synthesis

Each bond makes one water molecule

Special type of covalent bond – peptide bond

Peptide bond

Polymer = polypeptide- link many amino acids long, long chains

- Dehydration synthesis - Each bond makes a water moleculePeptide bond = between amino acids

Functions of Proteins

1. structure – many cell parts2. control chemical reactions (enzymes)3. transport substances (ex. Hemoglobin) 4. fight disease (antibodies)5. chemical messengers 6. movement (muscles)

Levels of Organization in Proteins

A protein's shape determines its function•Made of one or more polypeptide chains

folded into a unique shape•“Form follows function”•Must be a specific shape to act on another

molecule

Primary structurePrimary structure: the sequence of amino acids– assembled in ribosomes

Sequence is coded in DNA

Amino acids

More Complex StructureCoiling or folding in parts of the

polypeptide chain

• Chain folds into a 3-D shape– Depends on side groups that

interact• Two or more polypeptides can be

folded together• Hydrogen bonds connect different

areas on the molecule

What is a “protein”?• One or more polypeptides folded into a

specific, functional 3-dimensional shape

Collagen – in skin, joints hemoglobin – carries oxygen in the blood

How important is protein shape?

Normal hemoglobin – in red blood cells, carries oxygen

Sickle Cell Disease – abnormal shape of hemoglobin- carries less oxygen cell stress

wrinkles clogs tiny blood vessels

Sickled and normal red blood cell

Scanning Electron Microscope

Sickled red blood cells

Light microscope

Protein DenaturationDenature – lose shape (and function)Chemical or physical changes - break bonds that hold the 3-D shape

Denaturation can be caused by changes in ion concentration, pH, temperature, and others

Nucleic Acids

Elements: Carbon, Hydrogen, Oxygen, Nitrogen and Phosphorus Function: DNA – stores genetic & cell instructions RNA – uses DNA instructions to make proteins Monomer: nucleotide 3 parts: 5-carbon sugar phosphate group nitrogen base

LE 3-16a

Nitrogenousbase

5-carbon Sugar

Phosphategroup

Parts of a nucleotide

Bases:A – adenineT – thymineC – cytosineG – guanineU - uracil

LE 3-16b

Nucleotide

Sugar-phosphatebackbone

DNA - Polynucleotide

sugar-phosphate backbone

nitrogen bases bond to sugars

Nucleic Acid is a nucleotide polymer

DNA is two polymers of nucleotidesStructure: - Deoxyribose sugar - Hydrogen bonds hold two

polymer chains together at A-T and C-G

Function: - Base sequence on one chain

is a “gene” - Genes direct the amino acid

sequence in a protein - One molecule of DNA holds

thousands of genes

RNA is a single polymer chain

Structure: RNA – ribose sugar

Bases: A, C, G, and Uracil

Function: Carries a single gene

Uses the gene to make a protein

ALL ORGANISMS USE THE SAME GENETIC CODE

LE 3-16c

Basepair

Energy in Chemical Reactions

• Life processes are chemical • Need energy added (ACTIVATION ENERGY) to start reactions• Cells cannot use or make

heat • ENZYMES speed up reactions

– lower activation energy

Enzyme-substrate complex• Substrate – molecule an enzyme acts upon• Active site – region on enzyme molecule that binds to

substrate molecule - must fit together!!

Active sitesubstrate

Enzymes are “biologic catalysts”

catalyst - speeds reaction but is not changed or used up

enzymes are specific – act on only one kind of molecule

Two models for enzyme action: Induced fit – shape of enzyme changes when substrate attaches

Lock-and-key model – perfect fit, no shape change

Name – for chemical process or substrate; often end in -ase

How enzymes work

An anabolic reaction

Enzymes catalyze all reactions

A catabolic reaction

3-dimensional protein molecule - shape is critical

Temperature - heat makes molecules move faster

more contact between enzyme and substrate faster reaction rate

BUT, high temps denature proteins!

Factors Affecting Enzyme Action

Work best at a specific pH

- changes in pH break bonds holding molecule shape

Enzymes and pH

Enzyme activity and concentration

More enzyme or more substrate increase reaction rate

- BUT, only up to a point

• limiting reactant – all molecules being used

Enzyme InhibitorsCompetitive inhibitors - bind to active site - block substrate

Noncompetitive inhibitors - change shape of active site by binding somewhere else on the enzyme

Feedback inhibitors - a product made in the reaction binds to the enzyme, stops reaction