Exam 4 Practice Flashcards

Vocabulary flashcards for Exam 4 practice.

D-glucose

Commonly known as dextrose; a building block of cellulose; a monosaccharide with formula C6H12O6; the most common naturally occurring monosaccharide, but NOT a ketohexose.

Polymers of D-glucose

Amylose, Amylopectin, Cellulose are polymers of D-glucose; Insulin is not.

Cellulose

A polysaccharide found in plant cell walls, composed of β-glucose monomers, indigestible to humans due to β-1,4 glycosidic bonds forming strong hydrogen bonds between strands.

Lipids in biological membranes

Phospholipids are primarily involved in forming biological membranes like the myelin sheath.

Phospholipids vs. Triglycerides

Phospholipids have a phosphate group replacing one fatty acid chain, unlike triglycerides.

Saturated vs. Unsaturated Fats

Saturated fats pack more tightly due to straight chains, while unsaturated fats have kinks preventing tight packing.

18:1(Δ9) Notation

Indicates a fatty acid with 18 carbon atoms and one double bond at the 9th carbon from the carboxyl end.

Cholesterol and Bile Salts

Cholesterol is converted into bile salts, which act as emulsifiers to help digest lipids in the small intestine.

Hydrogenation of Unsaturated Fatty Acids

Primarily converts cis double bonds into trans double bonds, making the fatty acid more rigid.

Saponification Reaction

Triglyceride is broken down into glycerol and soap molecules (sodium salts of fatty acids) when treated with a strong base like NaOH.

Lipase

Enzyme primarily involved in the hydrolysis of triglycerides into fatty acids and glycerol.

Cis vs. Trans Fatty Acids

Cis fatty acids have a 'kink' in their structure due to hydrogen atoms being on the same side of the double bond.

Waxes

Composed of long-chain fatty acids esterified to long-chain alcohols, making them highly hydrophobic and water-resistant.

Oils vs. Solid Fats

Oils are composed of more unsaturated fatty acids, which tend to lower cholesterol levels, making them healthier than fats solid at room temperature.

Hydrolysis of Triacylglycerols

Produces fatty acids and glycerol in the presence of water and a catalyst such as lipase.

Glycerophospholipids Structure and Polarity

The glycerol backbone is hydrophilic, while the fatty acid tails are hydrophobic, giving the molecule both hydrophilic and hydrophobic regions.

Hormonal Proteins

Regulate body functions by acting as messengers, like insulin.

Primary Structure of Proteins

Refers to the unique sequence of amino acids in a polypeptide chain.

Kinases

Enzymes primarily responsible for adding a phosphate group to a substrate in cellular processes.

Protein Folding

Driven by the sequence of amino acids and the interactions between them, resulting in a specific 3D structure.

Enzyme Activity Regulation

Regulated by the binding of an allosteric inhibitor or activator to a site other than the active site.

Polar Amino Acids

Have side chains that can form hydrogen bonds with water and other polar molecules.

Disulfide Bonds

Disulfide bonds between cysteine residues that stabilize the 3D shape of the protein.

Protein Denaturation

The protein loses its three-dimensional structure but retains its primary sequence of amino acids.

Protein Structures

Secondary: alpha-helices; Tertiary: 3D shape; Quaternary: multiple polypeptides.

Blood

Blood is not made up of collagen.

Effect of Heat on R Groups in Protein

Heat disrupts hydrogen bonds and hydrophobic interactions between the R groups, causing the protein to unfold and lose its tertiary structure.

Non-competitive Inhibition

The inhibitor binds to an allosteric site, causing a change in the enzyme’s shape that reduces its activity, and this cannot be overcome by increasing substrate concentration.

Allosteric Inhibition

The inhibitor binds to a site other than the active site, changing the enzyme’s shape and reducing its activity.

Vitamin C

Vitamin C is not a fat-soluble vitamin.