BIology Chapter 3 Study Guide

organic compounds
Carbon-based molecules
hydrocarbons
organic molecules that are composed of only carbon and hydrogen
carbon skeleton
the chain of carbon atoms that forms the structural backbone of an organic molecule
macromolecule
A giant molecule formed by the joining of smaller molecules, usually by a condensation reaction. Polysaccharides, proteins, and nucleic acids are macromolecules
polymer
large compound formed from combinations of many monomers
carbohydrate
range from small sugar molecules (monomers) to large polysaccharides a large molecule consisting of many identical or similar parts major source of energy for the human body
We will write a custom essay sample on
Any topic specifically for you
For only $13.90/page
Order Now
monomer
a simple compound whose molecules can join together to form polymers
dehydration reaction
A chemical reaction in which two molecules covalently bond to each other with the removal of a water molecule.
hydrolysis
Breaking down complex molecules by the chemical addition of water
enzymes
Molecules, usually proteins or nucleic acids, that act as catalysts in biochemical reactions.
monosaccharides
The simplest carbohydrate, active alone or serving as a monomer for disaccharides and polysaccharides. Also known as simple sugars, the molecular formulas of are generally some multiple of CH2O.
disaccharide
any of a variety of carbohydrates that yield two monosaccharide molecules on complete hydrolysis
polysaccharide
long chains of sugar units that provide energy and structural support and are hydrophilic i.e. starch, glycogen, cellulose, chitin
starch
storage polysaccride made in plants, entirely, made of glucose monomers, helical shape, branched/unbranched
glycogen
also a glucose polysaccharide, more highly, branched compared to starch, stored in liver/muscle cells, provides energy, Only in animals not plans
cellulose
Most abundant organic compound
polymer of glucose
Parallel arrangement of H bonds fibril (provides support to plants), forms in tough walls of plant cells Most animals don’t have enzymes present to break down cellulose, Undigested fiber that moves through digestive system
Ex. Fruits, vegies, grains
chitin
structural polysaccharide Ex. Used by insects and crustaceans to build exoskeleton, In cell walls of fungi, Used as surgical thread
lipids
water insoluble (hydrophobic, or water fearing) compounds that are important in energy storage
fats
lipids made from glycerol and fatty acids (2 smaller molecules)
saturated
No double bonds is
saturated fats i.e. butter,
Beef fat solid at room temp
Too much can lead to disease, maximum hydrogens
unsaturated
Double bonds=unsaturated
Fats i.e. vegie oils, plant fats
Healthier, hydrogenated veg oil,
margarine, fewer hydrogens
phospholipids
Have two, rather than three, fatty acids attached to a molecule of glycerol, make up most of cell membrane, cluster into bilayers
steroids
are lipids composed of fused ring structures
cholesterol
a steroid that plays a significant role in the structure of the cell membrane
protein
is a polymer built from various combinations of 20 amino acid monomers
unique structures that relate directly to their functios
amino acid
the building blocks of proteins, have an amino group and a carboxyl group
covalent bonding R- groups different with each
peptide bond
links the carboxyl group of one amino acid to the amino group of the next amino acid, The covalent linkage
polypeptide
contains hundreds or thousands of amino acids linked by peptide bonds
sequence of amino acids creates a shape
Shape=function
primary level
protein is its unique amino acid sequence
sequence determined by genetic information A slight change in sequence can cause damaging results
secondary level
structure results from coiling or folding of the polypeptide coiling leads to helix (hair)
folding a pleated sheet (fibrous, spider silk)
alpha helix
A spiral shape constituting one form of the secondary structure of proteins, arising from a specific hydrogen-bonding structure.
beta pleated sheet
One form of the secondary structure of proteins in which the polypeptide chain folds back and forth, or where two regions of the chain lie parallel to each other and are held together by hydrogen bonds.
tertiary level
The overall three-dimensional shape of a protein, caused by interaction between R groups Special type of covalent bond called disulfide bridge Strengthens the shape of a protein, fibrous and globular, all proteins go to this level
quaternary level
Two or more polypeptide chains (subunits) ,creates a very strong protein
ex. Collagen (40% protein in human body) Bones, tendons, ligaments
Some are triple helix structures
denaturation
cause polypeptide chains to unravel and lose their shape and, thus, their function
Proteins can be by: chainging temp. increase (fever) Change salt concentration
pH changes Freezing will not denature proteins
nucleic acids
Amino acid sequence of polypeptide is programmed by a gene, DNA, RNA
DNA
nucleic acid, (biochemistry) a long linear polymer found in the nucleus of a cell and formed from nucleotides and shaped like a double helix
RNA
nucleic acid, (biochemistry) a long linear polymer of nucleotides found in the nucleus but mainly in the cytoplasm of a cell where it is associated with microsomes, single polynucleotide
nucleotide
monomer of nucleic acids made up of a 5-carbon sugar, a phosphate group, and a nitrogenous base
uracil
RNA Nitrogenous base
thymine
DNA Nitrogenous base
adenine
DNA RNA Nitrogenous base apirs with thymine
cytosine
DNA RNA Nitrogenous base
guanine
DNA RNA Nitrogenous base pairs with cytosine
double helix
Two polynucleotide strands wrap around each other to form