The Chemical Basis of Life: Organic Molecules Associated in Life
What are phospholipids?
A class of lipids, similar to triglycerides but connected to a phosphate group at the end instead of a fatty acid
What is a condensation reaction?
A condensation reaction takes place when two or more molecules combine into a larger one with the loss of a small molecule
What reactions cause proteins to be composed?
A dehydration or condensation reaction joins the monomers of amino acids into the polymer of a protein. They are broken apart by hydrolysis
What is a dehydration reaction?
A dehydration reaction is a condensation reaction in which the lost molecule is water.
What is a glycosidic bond?
A glycosidic bond is a bond formed between two sugar molecules.
What is a hydrolysis reaction?
A hydrolysis reaction is a process in which a polymer breaks down into a monomer and a molecule of water is added each time a monomer is released.
What is a monomer?
A monomer is made up of smaller molecules (building blocks)
What makes up a nucleotide?
A phosphate group, a five-carbon sugar, and a single or double ring of carbon and nitrogen atoms known as nitrogenous base
What is a polypeptide?
A polypeptide is an ordered, covalently linked colletion of amino acids without considering it's shape
What does the structure and function of a macromolecule depend on?
A structure and function of a macromolecule depends on the nature of the monomers and the number of monomers that are linked together. There is a three-dimensional way in which monomers are linked.
What makes up waxes?
All waxes contain one or more hydrocarbons and long structures. Most repel water providing a barrier to water loss
What are the stereoisomers of glucose?
Alpha and Beta glucose; the difference is a hydroxyl group of carbon above or below the ring.
What are amino acids?
Amino acids are monomer units which form the building blocks of proteins. The variable "R" group hold 20 different amino acids
Are amino acids polar or nonpolar?
Amino acids can be classified as nonpolar, polar and uncharged or polar and charged; this depends on the R group
Carboxyl
Can be found in amino acids and fatty acids
Phosphate
Can be found in nucleic acids, ATP, and is attached to amino acids
Hydroxyl
Can be found in steroids, alcohol, carbohydrates, and some amino acids
Ketone
Can be found in steroids, eicosanoids, waxes and proteins
What are carbohydrates composed of?
Carbohydrates are composed of carbon, hydrogen, and oxygen atoms; it's represented by a general formula as seen in the photo. Most of the carbon atoms in a carbohydrate are linked to a hydrogen atom and a hydroxyl group.
Why is carbon the chemical base of all life, and why that important?
Carbon is the chemical basis of all life because it has the ability to form 4 covalent bonds with another carbon and up to three other atoms. This is important because it allows a vast number of organic compounds to be formed from only a few chemical elements. Carbon also has the ability to form polar and nonpolar bonds.
What are the two types of geometric isomers?
Cisisomers and transisomers
What are the two classes of nucleic acids?
Deoxyribonucleic acid (DNA) and ribonucleic acid (RNA)
What are disaccharides?
Disaccharides are carbohydrates composed of two monosaccharides.
How are disaccharides joined and seperated?
Disaccharides are joined by dehydration or condensation reactions, and are broken apart by hydrolysis.
What are enantiomers?
Enantiomers are a pair of molecules that are mirror images
What are fats important for?
Energy storage, cushioning and insulation
What are fats?
Fats are a mixture of triglycerides known as triglycerols. They consist of glycerol bonded to three fatty acids.
What reactions cause fats to bond together and break apart?
Fats are joined through dehydration or condensation reactions. They are broken apart by hydrolysis.
What makes up steroids?
Four fused rings of carbon make up the skeleton of all steroids. Steroids are not highly soluble. Tiny differences in steroid structures can lead to huge differences in function
What are functional groups?
Functional groups are groups of atoms with special chemical features that contribute to the molecules' properties; each type of functional group exhibits the same properties in all molecules they appear in.
What are proteins composed of?
Generally, proteins are polymers composed of amino acids.
What are isomers?
Isomers are two different structures with an identical molecular formula but different structures and characteristics.
When a fatty acid is made up of only single bonds, what kind of fatty acid is it?
It's a saturated fatty acid
What are lipids?
Lipids are molecules composed predominantly of hydrogen and carbon atoms held together by nonpolar, covalent bonds.
What are the four major categories of macromolecules?
Lipids, carbohydrates, nucleic acids (DNA + RNA), and proteins
Why are protein-protein reactions important?
Many cellular processes involve steps in which two or more different proteins interact with eachother
Methyl
May be attached to DNA, proteins, and carbohydrates
Sulfate
May be attached to carbohydrates, proteins and lipids
What are monosaccharides?
Monosaccharides are the simplest sugars; they contain a simple monomer unit. Monosaccharides can join together to form larger carbohydrates.
What are trans fats?
Monounsaturated or polyunsaturated fat isomers with the hydrogens on opposite sides of the double bond
Carbonyl
Polar covalent - O is negative
What is a polymer?
Polymers are large molecules formed by linking together many monomers
What are polysaccharides?
Polysaccharides are made up of many monosaccharides successfully linked together to form long polymers
What are domains?
Portions within proteins that have distinct structures and functions
What are the four progressive levels of proteins?
Primary, secondary, tertiary and quaternary
Sulfhydryl
Proteins that contain the amino acid 'cystein'
RNA
RNA is less stable than DNA and usually consists of single rather that double strands. The pyrimidine Thymine is replaced in RNA with the pyrimidine base Uracil (U).
What are the two different ways to depict monosaccharide structures?
Ring or linear
Why have domains been duplicated during evolution?
So that the same ind of domain may be found in several different proteins
What are stereoisomers?
Stereoisomers have identical bonding relationships but different spatial positioning of the atoms.
What are sterols?
Steroids with a hydroxyl group
What are nucleic acids responsible for?
Storage, expression, and transmission of genetic information
What does DNA do?
Stores genetic information coded in the sequence of their monomer building blocks
What are structural isomers?
Structural isomers contain the same atoms but have different bonding relationships
What are sugars?
Sugars are small carbohydrates that may taste sweet.
The secondary structure of proteins
Takes place when the R groups of the amino acids of the primary structure react to one another. They will fold into either an alpha helix or a beta pleated sheet.
The primary structure of proteins
The amino acid sequence from beginning to end. Stabilized by the covalent peptide bonds that link adjacent amino acids together
phospholipids and their amphipathic feature
The amphipathic nature inside of water, allow the phospholipids to arrange into bi-layers. Their polar ends face out (water loving) and their nonpolar ends face one another in the interior (water fearing)
What configurations might these carbon bonds occur in?
The carbons bonds can occur in configurations that are linear, ringlike, or highly branched
What happens when the same domain is found in different proteins?
The domain has the same characteristic three-deminstional shape, chemical properties, and funtion
The quaternary structure of proteins
The quaternary structure is accomplished when a few tertiary structures bond together.
The tertiary structure of proteins
The tertiary structure will then be formed through the 3D shape of a single polypeptide.
Are phospholipids hydrophilic or hydrophobic?
They are both. One end is hydrophilic while the other is hydrophobic.
What is a lipids unifying characteristic?
They are hydrophobic and do not interact with water.
What are the random coiled regions of a protein?
They're regions along a polypeptide chain which does not assume an alpha helix or beta sheet confirmation
What is a trans isomer?
Two hydrogen atoms are on opposite sides of the double bond
What is a cis isomer?
Two hydrogen atoms linked to two carbons of a double bond are on the same side as the carbons
What is zwitteronic?
When one has both a positive and a negative charge
What is a polyunsaturated fatty acid?
When there are two or more double bonds between carbon-carbon.
What is a monounsaturated fatty acid?
When there is only one double bond between carbon-carbon
What are the four different nucleotides found in DNA?
Within purine bases: Adenine (A) and Guanine (G) - double ringed Within pyrimidine bases: Cytosine (C) and Thymine (T) - single ringed
Factors that influence protein structure
hydrogen bonds, ionic bonds and other polar interactions, hydrophobic effects, van der waals forces, disulphide bridges
Christian Anfinsen
postulated that proteins contain all the information necessary to fold into their proper conformation without the need for organelles or cellular factors
What does DNA consist of?
two polymers of deoxyribonucleotides coiled around eachother to form a double helix. They are held together by hydrogen bonds between a purine base and a pyrimidine base.
hydrophobic
water fearing
Hydrophilic
water loving