Post on 26-Dec-2015
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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