BCHEM 11 Flashcards
What are the stabilizing forces in molecules
- Covalent bonds (Sharing of e-)
- Ionic or electrostatic bonds (Transfer of e-)
- Hydrogen bonds (Sharing of H+, usually O & N)
- Hydrophobic Interactions (Np to NP)
Nucleophilic attack by water result in the cleavage of amides, glycosides or esters bonds that hold biopolymers together. This is known as ___
Hydrolysis
What does the external and internal layer of the phospholipids in the lipid bilayer contain?
External: Choline-containing phospholipid
Internal: Ethanolamine- and Serine-containing
What are the functions of each of the three types of fibers found in the cytoskeleton?
Microfilaments (thinnest) - for movement and mechanical support
Intermediate Filaments - stabilize position of organelles and for cell-cell attachment
Microtubules - determine the cell shape; function in the movement of organelles
T/F
The stronger the acid, the less protons will dissociate from it when added to water and the larger the value its Ka will have. This statement is:
False. Strong acids dissociate completely into anions and protons even in strongly acidic solutions (low pH). THE LOWER THE pKa, THE STRONGER THE ACID
These are organic molecules composed of carbon, hydrogen, and oxygen, and they serve as a primary source of energy in living organisms. It is the most abundant biomolecule on earth which composes 75% by mass pf plant materials and about 2/3 of human diet
Carbohydrates
It is the simplest carbohydrates, consisting of a single sugar unit. Examples include glucose, fructose, and galactose
Monosaccharide
What are chiral molecules and chiral centers?
chiral molecule is non superimposable
chiral center is an atom in a molecule that has 4 different groups bonded to it in a tetrahedral orientation. CHIRAL CENTERS FARTHEST FROM THE ALDEHYDE GROUP (2^n where n is the # of chiral centers)
What is the difference between alpha and beta glucose?
Alpha and beta glucose are two different conformations of the same monosaccharide. In alpha glucose, the hydroxyl (-OH) group on carbon 1 is below the ring, while in beta glucose, it’s above the ring.
ALPHATAAS / BETABABA
α - different direction on CH2OH and OH
β - same direction of CH2OH and OH
What are cyclic hemiacetals
Aldehyde or ketone reaction with alcohol.
C bonded with OH & OR are called hemiacetals or anomeric carbons
HEMIACETAL + OH = ACETAL
*Hemiacetal gives power to become reducing agent
What are the products of the oxidation of monosaccharides with :
i. weak oxidizing agents
ii. strong oxidizing agents
iii. enzymes in biologic system
i. Aldonic acid
ii. Aldaric acid
iii. Alduronic acid
What are the different types of disaccharides?
Maltose - Starch breakdown, α-1,4 glycosidic bonds
Cellobiose - cellulose breakdown; β-1,4 glycosidic bonds, reducing sugar
Lactose - Galac + Gluc; β-1,4 glycosidic bonds; reducing sugar
Sucrose - Fruc + Gluc; αβ-1,4 glycosidic bonds; nonreducing sugar (contains 2 acetal centers)
What is the difference between Starch(Amylopectin) and Glycogen?
Starch = Amylose + Amylopectin
Amylopectin branched every 25-30 units
Glycogen branched every 8 - 12 units; α-1,4 and α- 1,6
