Chapter 2: Chemistry Flashcards
Molecules
Groups of two or more atoms held together by chemical bonds.
Atom
Consists of a nucleus of positively charged protons and neutrally charged neutrons
Ionic Bonds
Bonds that form between two atoms when one or more electrons are transferred from one atom to the other.
Covalent bonds
Form when electrons between atoms are shared
Nonpolar Covalent bonds
Form when electrons are shared equally.
Polar Covalent Bonds
electrons are shared unequally
Hydrogen Bonds
Weak bonds between molecules
What are some special properties of water?
- Excellent Solvent
- High specific heat capacity
- Less dense in the solid form
- Strong cohesion and high surface tension
- Water has strong adhesion
Heat of Fusion
The energy required to change water from a solid to a liquid
Heat of Vaporization
The energy required to change water from a liquid to a gas
Cohesion
The attraction between like substances
Adhesion
The attraction of unlike substances
Organic Molecules contain…
carbon atoms
Polymer
Molecules that consist of a single unit (monomer) repeated several times.
Monosaccharide
The simplest kind of carbohydrate
Consists of a single sugar molecule like glucose or fructose
Condensation/Dehydration Reaction
When a small molecule(often water) is lost
Hydrolysis
When one molecule is split to form two molecules by the addition of water
Starch
A polymer of a-glucose molecules. It is the principal energy storage molecule in plant cells.
Glycogen
A polymer of a-glucose molecules. Differs from starch by its pattern of polymer branching. It is a major energy storage molecule in animal cells
Cellulose
Polymer of B-Glucose molecules. It serves as a structural molecule in the walls of plant cells and is the major component of wood.
Chitin
A polymer similar to cellulose, but each B-glucose molecule has a nitrogen-containing group attached to the ring. Chitin serves as a structural molecule in the walls of fungus cells and in the exoskeletons of insects, other arthropods, and mollusks.
What are the three formations of sugar?
Monosaccharide
Disaccharide
Polysaccharide
Lipid
Substance that is nearly insoluble in water, but highly soluble in Nonpolar substances
What are the three types of lipids?
Triglycerides
Phospholipid
Steroid
Triglyceride
Made of three fatty acids attached to a glycerol molecule
Saturated Fatty Acid
Has a single covalent bond between each pair of carbon atoms
Monounsaturated Fatty Acid
Has one double covalent bond, and each of the two carbons in this bond has only one hydrogen atom bonded to it.
Polyunsaturated Fatty Acid
Like a monounsaturated fatty acid except that there are two or more double covalent bonds.
Phospholipid
Has two fatty acid chains and one phosphate group attached to a glycerol molecule.
Steroids
Characterized by a backbone of four linked carbon rings.
Proteins can be classified in what 5 catagories?
Structural Storage Transport Defensive Enzymes
DNA Makeup
a nitrogen base, a five-carbon sugar called deoxyribose, and a phosphate group
Catalyst
Any substance that accelerates a reaction but does not undergo a chemical change itself
Catabolism
Breakdown of substances
Synthesis or Anabolism
The formation of new products
Enzyme
Globular proteins that act as catalysts for metabolic reactions
Substrate
The substance or substances upon which the enzyme acts.
What are some facts about enzymes?
Enzymes are substrate specific
Enzymes are unchanged as a result of a reaction
An enzyme catalyzes a reaction in both forward and reverse directions
The efficiency of an enzyme is affected by temperature and pH
The induced-fit model describes how enzymes work
Cofactors
Nonprotein molecules that assist enzymes
Coenzymes
Organic cofactors that donate or accept some component of a reaction, often electrons
Inorganic cofactors
Often metal ions
Allosteric Activator
Binds to the enzyme and induces the enzyme’s active form
Allosteric Inhibitor
Binds to the enzyme and induces the enzyme’s inactive form
Feedback inhibition
an end product of a series of reactions acts as an allosteric inhibitor, shutting down one of the enzymes catalyzing the reaction series
Competitive Inhibition
A substance that mimics the substrate inhibits an enzyme by occupying the active site. The mimic displaces the substrate and prevents the enzyme from catalyzing the substrate
Noncompetitive Inhibition
A substance inhibits the action of an enzyme by binding to the enzyme at a location other than the active site
Cooperativity
An enzyme becomes more receptive to additional substrate molecules after one substrate molecule attaches to an active site.
