Date post: | 01-Jan-2016 |
Category: |
Documents |
Upload: | alberta-ward |
View: | 228 times |
Download: | 0 times |
2.3 Carbon-Based Molecules
KEY CONCEPTCarbon-based molecules (proteins, lipids, carbohydrates and nucleic acids) are found in all organisms. These molecules form all the structures and carry out the functions of all life.
2.3 Carbon-Based Molecules
• Carbon atoms are considered the building blocks of life Carbon atoms are considered the building blocks of life because they :because they :
1. They form most of the structures in living things1. They form most of the structures in living things
(Structure)(Structure)
2. Carry out most processes that keep organisms alive 2. Carry out most processes that keep organisms alive
(Function) (Function)
Each molecules structure is unique and is specific to its job Each molecules structure is unique and is specific to its job or function in living things.or function in living things.
..
2.3 Carbon-Based Molecules
Why is Carbon so special?
• Carbon has Carbon has fourfour valence electrons. valence electrons.
• It It sharesshares these electrons with other atoms these electrons with other atoms to form molecules that are held together by to form molecules that are held together by strong strong covalentcovalent bonds. bonds.
.
2.3 Carbon-Based Molecules
Molecules that contain carbon are called
Organic compounds.
Exceptions are CO(Carbon monoxide) and
CO2 (Carbon dioxide)
There are over 2 million known organic compounds. They are made and found only in living things.
2.3 Carbon-Based Molecules
There are 3 basic shapes of carbon-based compounds depending on how the carbon atoms are bonded together:
• straight chainstraight chain• branched chainbranched chain• ringring
2.3 Carbon-Based Molecules
• Large carbon-based molecules are made of many Large carbon-based molecules are made of many repeating small subunits that are bonded together.repeating small subunits that are bonded together.
Smaller individual molecular subunits are called Smaller individual molecular subunits are called MonomersMonomers
Ex. GlucoseEx. Glucose
CC66HH1212OO66
2.3 Carbon-Based Molecules
Larger molecules made when monomers Larger molecules made when monomers bond are called bond are called PolymersPolymers..
2.3 Carbon-Based Molecules
The reaction that joins monomers to form polymers is called Dehydration Synthesis.
• Animation
Dehydration synthesis means “to make by removing water.” (Dehydration – remove water Synthesis – to make)
2.3 Carbon-Based Molecules
• Polymers can be broken down into the monomers that made them through Hydrolysis
• Hydrolysis means “to break by adding water”
2.3 Carbon-Based Molecules
Four major groups of organic compounds in living things:
• Carbohydrates
• Lipids
• Proteins
• Nucleic Acids
Quick Check for Understanding –
What atom do all these molecules contain?
2.3 Carbon-Based Molecules
Four major groups of organic compounds in living things:
• Carbohydrates
• Lipids
• Proteins
• Nucleic Acids
2.3 Carbon-Based Molecules
Quick Check for Understanding –
What atom do all these molecules contain?
2.3 Carbon-Based Molecules
Quick Check for Understanding –
What atom do all these molecules contain?
CARBON
2.3 Carbon-Based Molecules
Carbohydrate molecules are made of Carbon (C), Hydrogen (H), and Oxygen (O) atoms
2.3 Carbon-Based Molecules
• Food that contain primarily carbohydrate molecules are called Sugars (simple carbohydrates) and Starches (complex carbohydrates).
2.3 Carbon-Based Molecules
3 Categories of Carbohydrates based on Size:
1.Monosaccharides (smallest)
2.Disaccharides
3. Polysaccharides (largest)
2.3 Carbon-Based Molecules
1. 1. Monosaccharide: one single molecule
• 11. Glucose – made in photosynthesis;– made in photosynthesis; blood sugar
2. Galactose - Component of milk sugar
3. 3. Fructose - - fruit sugar
4. 4. Deoxyribose and Ribose – – in nucleic acids
glucoseglucose
2.3 Carbon-Based Molecules
2. Disaccharide – 2 monosaccharides joined together
1. Sucrose – table sugar (glucose + fructose)
2. Lactose – milk sugar (glucose + galactose))
fructosefructoseglucoseglucose
2.3 Carbon-Based Molecules
3.3. Polysaccharides - Polysaccharides - manymany monosaccharides joined monosaccharides joined togethertogether
11. . Starch Starch – glucose storage in plants (bread, taters)– glucose storage in plants (bread, taters)
2. 2. GlycogenGlycogen – glucose storage in animals – glucose storage in animals
3. 3. CelluloseCellulose – forms plant cell walls – forms plant cell walls
4. 4. ChitinChitin – forms insect exoskeletons and – forms insect exoskeletons and
fungus cell wallsfungus cell walls
glucoseglucoseglucoseglucose
glucoseglucoseglucoseglucose
glucoseglucoseglucoseglucose
glucoseglucoseglucoseglucose
cellulosecellulose
2.3 Carbon-Based Molecules
Carbohydrate molecules can have the same monomers but they are joined together differently
.
Polymer (starch)
Starch is a polymer of glucose monomers that often has a branched structure.
Polymer (cellulose)
Cellulose is a polymer of glucose monomers that has a straight, rigid structure
monomer
2.3 Carbon-Based Molecules
• REMEMBER A UNIFYING THEME:
• The structure of a molecule affects its function
2.3 Carbon-Based Molecules
• Uses of Lipids in Living Things:
1.Stores large amounts of chemical energy
2.Provide warmth and insulation
3. #1 component of cell membranes
4. Makes hormones the body’s chemical
messengers
2.3 Carbon-Based Molecules
Common Features of Lipids
1. Nonpolar molecules – no charge on atoms
2. Hydrophobic – Don’t dissolve in water
3. No specific monomer found in all lipids.
Many lipids do contain fatty acid molecules.
2.3 Carbon-Based Molecules
• The 100’s of different types of fatty acid molecules have the same basic structure
2.3 Carbon-Based Molecules
3 Categories of Fatty Acids
No double bonds
between Carbon atoms
No kinks
One or more double bonds between carbon atoms
Molecule has kinks and bends
2.3 Carbon-Based Molecules
If the Fatty Acid molecules have :
•Single bonds between C atoms –
Saturated Fats (Bad fats in diet)
•Double bonds between C atoms –
Unsaturated Fats (Good fats in diet)
(Copy what’s underlined below into notes)
•LDL - Lousy for you Want # to be LOW
•HDL - Happy for you Want # to be HIGH
2.3 Carbon-Based Molecules
•Uses of Proteins in Living Things:
•Make chemical reactions go faster (Enzymes)
•Move molecules in/out of cells
•Help cells move
•Receptors on cell surfaces
2.3 Carbon-Based Molecules
Monomers of Proteins: Amino Acids
• 20 different amino acids molecules linked by a special bond called a peptide bond.
• 9 amino acids are Essential – Can only be obtained by eating food
2.3 Carbon-Based Molecules
Don’t forget: Proteins are BIG molecules Don’t forget: Proteins are BIG molecules
made by joining SMALL amino acid moleculesmade by joining SMALL amino acid molecules
.
Protein – Polymer
Amino Acids - Monomers
2.3 Carbon-Based Molecules
Basic structure of all known 20 amino acids
Amine group Carboxylic acid group
Variable group
2.3 Carbon-Based Molecules
• .Amino acids are joined by peptide bonds .Amino acids are joined by peptide bonds which form between them through which form between them through dehydration synthesisdehydration synthesis
.
OH + H
OH + H
2.3 Carbon-Based Molecules
Examples of Protein Molecules in Living things:
• 1. Albumin – protein in egg white
• 2. Amylase – breaks apart starch to glucose through hydrolysis. Enzyme found in your saliva
• 3. Keratin – protein in hair, feathers and nails
• 4. Hemoglobin – in red blood cells, oxygen attaches to it to be carried throughout the body and delivered to all cells
2.3 Carbon-Based Molecules
Two Types of Nucleic Acid Molecules:
1. Deoxyribonucleic Acid - DNA
2. Ribonucleic Acid – RNA
Uses of Nucleic Acids:
1. Stores hereditary information
2. Helps to make protein molecules
2.3 Carbon-Based Molecules
• Monomers of Nucleic acids are nucleotides.
• 1000’s of nucleotides join together to make a nucleic acid.
2.3 Carbon-Based Molecules
3 Molecules Join Together to form a Nucleotide
1. Sugar
2. Phosphate group
3. Nitrogen containing base (5 kinds).
A phosphate group nitrogen-containing molecule,called a base
deoxyribose (sugar)