BIOMOLECULES
Molecules are either inorganic compounds or organic compounds
Organic-has carbon
Inorganic-no carbon
Why is carbon so special?
It can form 4 bonds with other atoms. It loves to COVALENTLY BOND!
It can form single, double, and triple bonds.
There are 4 types of biomolecules in our bodies
Carbohydrates
Lipids (fats)
Proteins
Nucleic acid (DNA)
These are large molecules (polymer) that are made up of smaller building blocks (monomers)
Polymers are made of monomers.
Carbon is the central element
All biomolecules contain a Carbon chain or ring
Carbon has 4 outer shell electrons (valence = 4)
Therefore it’s bonding capacity is great
It forms covalent bonds –hence, has strong bonds
Once bound to other elements (or to other Carbons), it is very stable
The 4 types of biomolecules often consist of large carbon chains
Carbon binds to more than just hydrogen.
To OH groups in sugars
To NH2 groups in amino acids
To H2PO4 groups of nucleotides of DNA, RNA, and ATP
Monomers are made into polymers via dehydration reactions
Polymers are broken down into monomers via hydrolysis reactions
PROTEINS
Composed of chains of amino acids
Elements: C, H, O, N, or S (sulfur)
Structure: look for N or S
20 amino acids exist
Amino acids contain
Central Carbon
Amine group
Carboxyl group
What do they do
Hemoglobin in your blood that carries oxygen
Muscles, tendons, hair
Defend body from microorganisms
Control chemical reactions-enzymes
Carry out almost all of the body’s everyday functions
Building block-amino acids
The chain (polymer) of amino acids forms a variety of loops, coils, and folded sheets from an
assortment of bonds and attractions between amino acids within the chain(s)
There are at least 7 functions of proteins
Enzyme catalysts – specific for 1 reaction
Defense – antibody proteins, other proteins
Transport- Hgb, Mgb, transferrins, etc
Support – keratin, fibrin, collagen
Motion – actin/myosin, cytoskeletal fibers
Regulation- some hormones, regulatory proteins on DNA, cell receptors
Storage – Ca and Fe attached to storage protein
There are four levels of protein structure
Primary = sequence of aa’s
Secondary = forms pleated sheet, helix, or coil
Tertiary = entire length of aa’s folded into a shape
Quaternary = several aa sequences linked together
*A protein’s shape is very important
*You change the shape of a protein, you change the function or lose the function
CARBOHYDRATES
Elements-C, H, O
Function: Main source of energy, gives plants tough structure
Examples: sugars and starches, glycogen, sucrose, glucose, cellulose
Shape-rings connected
Building Block-monosaccharide or simple sugars (glucose)
Simple sugars (monosaccharides)
Different types of carbohydrates
Only one 3-C, 5-C, 6-C chain or ring
involved
Fructose - fruit
Galactose - milk
*Based on size
Monosaccharide-one sugar
Glucose, galactose (found in milk), fructose (found in fruit)
Disaccharide-two sugars
lactose
Polysaccharide-many sugars
Cellulose-makes plants have a rigid structure
Glycogen-animal starch
Simple sugars (monosaccharides)
Only one 3-C, 5-C, 6-C chain or ring involved
LIPID (FATS)
(hydrophobic)
Elements-C, H, O
Has the most energy but we can’t consume tons of fat; part of membranes; insulation
Structure-long chain of carbons attached
Examples: cholesterol, wax, steroids, oils
Building Block-fatty acids and glycerol
Central core of glycerol
Bound to up to 3 fatty acid chains
They exhibit a high number of C-H bonds – therefore much energy and non-polar
When placed in water, lipids spontaneously cluster together
They help organize the interior content of cells “phospholipids”
Saturated vs. Unsaturated
Saturated-bad for you; causes cholesterol problems, clogged arteries; solid at room
temperature; lard
Unsaturated-liquid at room temperature; not as bad for you; olive oil, canola oil,
peanut oil
Trans fat-type of unsaturated; causes coronary heart disease
Phospholipids and cell membranes
P-lipids make up the majority of cell membranes including:
The plasma membrane
Nuclear envelope
Endoplasmic reticulum (ER)
Golgi apparatus
Membrane-bound vesicles
Cell environment organizes P-lipid bilayer to proper orientation
Hydrophilic (polar) “heads” of P-lipid oriented to the exterior; hydrophobic (non-polar)
“tails” oriented to the interior
Nucleic acids: DNA and RNA
DNA = deoxyribonucleic acid
DNA is a double polymer (chain)
Each chain is made of nucleotides
The 2 chains bond together to form a helix
Each nucleotide in DNA contains:
5-C sugar
(deoxyribose)
Phosphate
Nitrogen base
-adenine (A)
-guanine (G)
-cytosine (C)
-thymine (T)
