Chapter 1 Flashcards
(20 cards)
What type of bond occurs when a metal loses electrons and a non-metal gains them?
Ionic bond
Ionic bonds are formed due to the electrostatic attraction between oppositely charged ions.
What is the difference between polar and nonpolar covalent bonding?
Polar covalent: unequal sharing of electrons (△EN= 0.4-1.7)
Nonpolar covalent: equal sharing of electrons (△EN< 0.4)
The difference in electronegativity (△EN) determines the type of covalent bond.
What is the strongest van der Waals force and its biological significance?
Hydrogen bonding
Hydrogen bonds are crucial for the structure and function of biomolecules.
What type of linkage joins monosaccharides into larger carbohydrates?
Glycosidic linkage
This linkage is essential for forming disaccharides and polysaccharides.
What is a peptide bond?
A covalent bond between the amino group and carboxyl group of two amino acids
Peptide bonds are formed through dehydration reactions.
What type of bond connects nucleotide subunits in nucleic acids?
Phosphodiester bond
Phosphodiester bonds link the sugar and phosphate groups of nucleotides.
What reaction occurs when a glycerol molecule reacts with fatty acids?
Ester bond formation
This is a condensation reaction between hydroxyl and carboxyl groups.
Fill in the blank: Dehydration reactions are used by cells to synthesize larger molecules, such as when _______ bond together to make polypeptides.
amino acids
What is the opposite of a dehydration reaction?
Hydrolysis reaction
Hydrolysis uses water to split molecules into smaller subunits.
What is the primary structure of a protein?
Specific linear sequence of amino acids
A polypeptide can have many different sequences due to the variety of amino acids.
What characterizes the secondary structure of proteins?
Folds and coils due to hydrogen bonding
Examples include β-pleated sheets and α-helices.
What determines the tertiary structure of a protein?
Intermolecular reactions between R-groups
These interactions include ionic bonds, hydrogen bonds, hydrophobic interactions, and disulfide bridges.
What is the quaternary structure of a protein?
Aggregation of two or more polypeptide chains
Examples include collagen and hemoglobin.
What is denaturation in the context of proteins?
The unraveling or change in shape of a protein due to environmental factors
Factors include pH, salt concentration, and temperature.
What term describes the energy required for a chemical reaction to occur?
Activation energy (EA)
Enzymes lower the activation energy needed for reactions.
What role do cofactors play in enzyme activity?
Essential non-proteins that bind to enzymes
Often metals such as Fe, Cu, Zn, and Mn.
What are coenzymes?
Organic molecules derived from vitamins that assist enzymes
An example is NAD, an electron carrier.
Define competitive inhibitors.
Molecules that resemble the substrate and block the active site
They compete with the substrate for binding.
What are noncompetitive inhibitors?
Molecules that bind to a different site on the enzyme, altering its shape
They do not compete with the substrate for the active site.
What is allosteric regulation?
Regulation of enzyme activity through binding at an allosteric site
Can either inhibit or stimulate enzyme function.
