CHP 3 BIOL 2311 Flashcards
What are the 6 most common elements in biological molecules?
Carbon, Hydrogen, Nitrogen, Oxygen, Phosphorous, Sulfur
Define a molecule
A chemical substance that results from the combination of two or more atoms
Define a compound
Molecules that are combinations of two or more different elements
What are the three types of chemical bonds? Describe them
Covalent bonds: non-polar equal sharing of electrons, polar unequal sharing of electrons
Ionic Bonds: electrons that are transferred to one atom forming positively charged cations and negatively charged anions.
Hydrogen Bonds: Electrostatic attraction between Hydrogen and Nitrogen or Oxygen.
What is a solution? Describe it.
A mixture of one or more substances called solutes, dispersed in a dissolving medium called a solvent.
Describe the three types of molecules found within aqueous solutions and their relationship to water
Hydrophilic molecules, dissolve in water.
Hydrophobic molecules, repel water.
Amphipathic molecules, have both hydrophilic and hydrophobic properties
Why is water so special within biology?
Liquid at most earth temperatures, it resists temperature changes, it is a superb solvent, it has high cohesion, adhesion and tension due to hydrogen bonds, acts as a buffer.
What do organic and inorganic compounds contain?
Organic compounds contain carbon bonded to hydrogen
Inorganic compounds lack carbon and hydrogen such as CO2.
What is pH?
It ranges from 0-14 and expresses the concentration of H+ ions.
What are the four major classes of organic molecules within a living organism?
Carbohydrate, lipids, proteins, and nucleic acids.
What is a hydrocarbon?
Molecules consisting of carbon linked only to hydrogen atoms.
How many unpaired outer electrons does carbon contain?
4
What is the simplest hydrocarbon?
CH4 (Methane) it consists of a single carbon atom bonded to four hydrogen atoms.
What is Chemical Evolution?
It resulted in the first forms of life on Earth after formation of organic molecules.
What are functional groups and which one most frequently enter into most biological reactions?
Functional groups are small reactive groups of atoms which give larger molecules specific chemical properties.
Functional groups that enter most frequently into biological reactions are the hydroxyl, carbonyl, carboxyl, amino, phosphate, and sulfhydryl groups.
What are isomers?
Molecules that have the same chemical formula but different molecular structures.
What are stereoisomers?
Isomers that are mirror images of each other such as glyceraldehyde
What are structural isomers?
Two molecules with the same chemical formula but atoms are arranged in different ways. EX: glucose, an aldehyde and fructose, a ketone.
What is a dehydration synthesis reaction?
When water components are removed from a group. New covalent bonds join subunits into a larger molecule.
What is hydrolysis?
When water components are added. Covalent bonds are broken, splitting a molecule into smaller subunits.
The 4 Biological Macromolecules
Carbohydrates, Lipids, Proteins, Nucleic Acid
What are Monomers
A repeating subunit
What are polymers
Chain of monomers
What are large polymers, what are they assembled from and connected by what chain?
Large polymers are carbohydrates, lipids, proteins, and nucleic acid, assembled from subunit molecules (monomers), connected by a chain of covalent bond.
Energy providing carbohydrates are called what?
In a plant cell it is stored as starch, in an animal cell it is stored as glycogen
What is a polymer with a mass of 1,000 daltons or more?
A macromolecule
What is the ratio of Carbon Hydrogen and Oxygen?
1C:2H:1O
How many carbon atoms are inside of a single Monosaccharides?
3-7 carbon atoms
What is a disaccharide?
Two monosaccharides polymerize to form a disaccharide.
What are polysaccharides?
Carbohydrate polymers with more than 10 linked monosaccharide monomers
What are the most common monosacccharides?
three carbons, five carbons, six carbons
In carbohydrates what are the subunits linked by?
Glycosidic bonds
What are lipids?
Water insoluble nonpolar molecules made mostly of hydrocarbons
What are the three most common type of lipid molecules? Explain.
Neutral lipids: stores and used as an energy source
Phospholipids: form cell membranes
Steroids: serve as hormones that regulate cellular activities.
What is the charge of Neutral lipids and what are the two types of neutral lipids?
Nonpolar: no charge, oils and fats.
How do triglycerides form? How do the covalent bonds form?
Triglycerides form by dehydration synthesis between three carbon glycerol (an alcohol) and three fatty acid side chains.
The covalent bond forms between -COOH group of the fatty acid and the -OH group of the glycerol.
What is the most common fatty acid chains?
14-22 carbons
What happens as the chain length increases?
As chain length increases, fatty acids become less water-soluble and more oily.
What is a saturated fatty acid?
Fatty acid binds the maximum number of hydrogen atoms, only single bonds exist between carbon atoms.
What are monounsaturated and polyunsaturated acids?
Fatty acids with one double bond are monounsaturated, and acids with more than one double bond is polyunsaturated.
What is the difference between unsaturated and saturated fatty acids?
Unsaturated fatty acids (vegetable oils): bend at a double bond and are more fluid at biological temperature.
Saturated fatty acids are found in solid animal fats like butter.
Triglycerides serve as ______ within animals.
Energy reserves
How are waxes formed?
Fatty acids combine with long chain alcohols or hydrocarbon structure to form wax.
What is the primary lipids of cell membranes?
Phospholipids
What is the chemical framework of steroids?
Lipids with structure of four carbon rings.
What are sterols, explain their framework.
It is the most common steroid, they have a single polar OH group linked to one end of the ring framework and a complex, nonpolar hydrocarbon
What are steroid hormones?
They control development, behavior and several internal biochemical processes
Name the 2 most common steroid sex hormones
Estrogen and testosterone
What purpose do Chlorophylls and carotenoids serve?
They are pigments that absorb light and help convert it to chemical energy in plants.
What is the predominant molecule in cells.
Proteins
What purpose do proteins serve in a cell?
They are essential to cell structure and function. The enzyme provide structural support, movement, transport and regulation of proteins and DNA.
What is the subunit of protein
Monomer
What are monomers made up of?
amino acids
What are polymers made up of
A monomer chain, peptides
How many amino acids to organisms use to build proteins?
20
Can amino acids serve as an acid or a base?
They can serve as both
What do covalent peptide bonds do?
They link amino acids into polypeptide chains.
How are peptide bonds formed?
They are formed by a dehydration synthesis reaction between the NH2 group of one amino acid and the other COOH group of another amino acid.
How are polypeptides structured?
A growing polypeptide chain has an N terminal end and a C terminal end. New amino acids are linked only to the C terminal end.
What links amino acids to form proteins?
Peptide bonds
What are the four levels of protein structure? Describe them
Primary structure, the unique sequence of amino acids forming a polypeptide bond. Secondary structure, produced by the twists and turns of the amino acid chain. Tertiary structure, the folding of the amino acid chain, with its secondary structures into the overall 3-D shape of a protein. Quaternary structure, when present, is formed from more than one polypeptide chain.
What happens if you alter an amino acid in the primary structure?
It will alter secondary, tertiary, and quaternary structures which can alter or destroy biological function
What is denaturation?
Unfolding a protein from its active conformation so that it loses its structure and function.
What are chaperonins?
Proteins that bind temporarily with newly synthesized proteins, direction their conformation toward the correct tertiary structure and inhibiting incorrect arrangements.
What are domains?
In proteins folding of the amino acid chain produce large subdivisions
What is the monomer of nucleic acids?
nucleotides, it consists of three parts linked together by covalent bonds
What are the two types of nitrogenous bases
Pyrimidines and purines
What is a nucleoside?
A structure containing only a nitrogenous base and five carbon sugar
What are DNA double helix held together by?
Two polynucleotide chains are held together by hydrogen bonds.
DNA and RNA are consisted of what?
Phosphodiester bonds
What is the structure of a DNA molecule?
Double helix, two polynucleotide chains wrapped around each other in a spiral that resembles a twisted ladder.
How is ATP made?
It is produced by dehydration synthesis
How is ATP broken down
It is broken down by hydrolysis
