Module 2: The chemical Basis of Life Flashcards
What is hypothesized that the earliest cells were made up of?
Nucleic acids and membrane
What are polar molecules?
Molecules with a symmetric distribution of charge.
What are non-polar molecules?
Molecules that lack electronegative atoms and strongly polarized bonds.
What 3 kinds of non-covalent bonds are there?
- Ionic bonds
- Hydrogen bonds
- Van der Waals forces
What is an ionic bond?
Attraction between charged atoms.
What is a hydrogen bond?
Partially positive when covalently bonded to electronegative atom, can approach second electronegative atom to form hydrogen bonds.
What are Van der Waals forces?
Hydrophobic interaction, non-polar molecules lack charged regions and forced into aggregates to reduce water exposure.
Does an acid release or accept protons?
Release protons.
Does a base release or accept protons?
Accepts protons.
What are amphoteric molecules?
Act as either acid or base.
What is a buffer?
Resist changes in pH.
How is acidity measured?
Measured in the pH scale.
What are the four macromolecules?
Proteins, nucleic acids, polysaccharides, and certain lipids.
Define: Carbohydrates
Includes simple sugars and all larger molecules constructed of sugar building blocks.
What is the primary function of carbohydrates?
Stores of chemical energy and as material for biological construction.
Why are sugars highly water soluble?
Due to hydroxyl groups
Define: Polysaccharides
Identical sugar monomers but different properties, polymers of sugars joint by glycostatic bond.
Define: Glycogen
Animal product, made of branched glucose polymers.
Define: Starch
A plant product made
of both branched and
unbranched glucose polymers.
What can lipids dissolve in?
In organic solvents but not water.
What are three types of lipids?
- Fats
- Steroid
- Phospholipids
Describe lipid structure.
Made of a glycerol backbone, 2 fatty acid tails and a phosphate group.
What fatty acids are considered saturated? (Double bond, no double bond)
Fatty acids that lack double bonds.
What fatty acids are considered unsaturated? (Double bond, no double bond)
Fatty acids with double bonds.
What is the structure of a steroid?
Steroids are built around a
four-ringed hydrocarbon skeleton.
What is the precursor for steroid hormones?
Cholesterol.
What is the structure of a phospholipid?
- A phospholipid molecule
resembles a fat but has only two fatty acid chains not three (a diacylglycerol). - The third hydroxyl of glycerol is bonded to a phosphate group.
What macromolecule carries out the cells activity?
Proteins.
What is the building block of a protein?
Amino acids.
What do all amino acids have?
There are 20 different amino acids with different chemical properties. They all have a carboxyl and an amino group, separated by a single carbon atom, the alpha-carbon.
What helps stabilize proteins shape?
Disulfide bridges.
What is the driving force during protein folding and stability?
Hydrophobic interactions are a driving force during protein folding and cntribute substantially to the overall stability of the protein.
Define: Primary structure of proteins.
Amino acid sequence of the proteins, linear sequence of amino acid that constitutes the chain.
Define: Secondary structure of proteins.
Confirmation of portions of the polypeptide chain
Define: Tertiary structure of proteins.
Confirmation of entire polypeptide.
What was the first tertiary to structure that was determined?
Myoglobin
How is tertiary structure most categorized?
By shape as fibrous proteins that are elongated, or globular which are compact.
Define: Quaternary structure
Proteins composed of subunits.
Define: Denaturation
Unfolding of a protein.
What can cause denaturation?
Detergents, organic solvents, radiation, heat, and compounds like urea.
Define: Proteome
Entire inventory of proteins that is produced by an organism and is applied to inventory of all proteins also present in partial tissue, cell, cellular organelle.
Define: Proteonomics 
Coined to describe expanding field of proteins biochemistry
Define: Nucleic acids
Polymers of nucleotides that store and transmit genetic information.
What is DNA what does it stand for? and consists of?
DNA holds the genetic info in all cellular organisms. Deoxyribonucleic acid. Contains the sugar deoxyribose, has a hydrogen atom attached to the 2nd carbon. Double stranded.
What is RNA? what does it stand for? and consists of?
Is a single stranded structure. Ribonucleic acid. Contains sugar ribose, has a hydroxyl group bonded to the 2nd carbon. May have catalytic activity, such RNA enzymes are called ribozymes.
What holds genetic information in all cellular organisms and some viruses?
DNA
What does each nucleotide consist of?
Consists of 3 parts, a sugar, a nitrogenous base, and a phosphate.
What transfers information from the DNA?
RNA.
What does each base pairs bind to?
Adenine (A) binds to Thymine (T)
Cytosine (C) binds to Guanine (G)
