Biochemistry, Solution Chemistry, Buffers, and Carbohydrate Metabolism Flashcards

Vocabulary practice flashcards covering physical chemistry of solutions, biological buffers, non-covalent interactions, carbohydrates, homopolysaccharides, glycosaminoglycans, and diabetes mellitus biochemistry based on lecture notes.

Molarity

The number of moles of solute dissolved per liter of solution, expressed in units of $moles\,l^{-1}$ or $M$.

Molality

The number of moles of solute per kilogram of solvent, expressed in units of $moles\,kg^{-1}$.

Normality

The number of gram equivalents of solute per liter of solution ($N = \frac{\text{Gram eq. wt}}{\text{Vol. in L}}$).

Equivalent Weight

The molecular weight of a compound divided by its acidity or basicity in an acid-base reaction.

Covalent Bonds

Chemical bonds formed by the sharing of electrons, including disulphide, peptide, glycosidic, and phosphodiester bonds.

Non-Covalent Bonds

Interactions formed without sharing electrons, including hydrogen bonds, hydrophobic interactions, electrostatic interactions, and Van der Waals interactions.

Hydrophobic Interaction

The tendency of nonpolar molecules to repel water and aggregate together in aqueous solution.

Electrostatic Interactions

Attractive or repulsive forces between charged particles or molecules, such as between negatively charged DNA and positively charged histone proteins.

Van der Waals Interactions

Weak interatomic forces that occur only when two uncharged atoms come very close to each other, such as base pair stacking in DNA.

Water Molecule Structure

A tetrahedral geometry with an oxygen atom covalently bound to two hydrogen atoms at a bond angle of $104.5^\circ$, with two non-bonding lone pairs at the remaining corners.

Osmosis

The movement of solvent particles across a concentration gradient from an area of high solvent concentration to low solvent concentration.

Diffusion

The passive movement of solute particles dissolving evenly throughout a solvent, occurring with or without a semipermeable membrane.

Brønsted-Lowry Acid and Base

An acid is defined as a proton ($H^+$) donor, while a base is defined as a proton ($H^+$) acceptor.

Weak Acid

An acid that ionizes only partially in an aqueous solution, such as oxalic acid or succinic acid.

Strong Acid

An acid that ionizes rapidly and completely by transferring $H^+$ to $H_2O$, such as $HCl$ or $H_2SO_4$.

Ion Product of Water ($K_w$)

The product of hydrogen and hydroxide ion concentrations in pure water, equal to $10^{-14}$ at $25^\circ C$.

Sørensen's pH Scale

A logarithmic measure of hydrogen ion concentration defined as $pH = -\log_{10}[H^+]$.

Henderson-Hasselbalch Equation

An equation relating pH to $pK_a$ and conjugate base/acid concentration: $pH = pK_a + \log\left(\frac{[A^-]}{[HA]}\right)$.

Buffer Solution

A solution consisting of a weak acid and its conjugate base that resists changes in pH when small amounts of $H^+$ or $OH^-$ are added or removed.

Metabolic Acidosis

A physiological reduction in blood pH below the normal range ($7.35 - 7.45$), which can result from starvation or diabetes.

Metabolic Alkalosis

A physiological increase in blood pH above the normal range ($7.35 - 7.45$), which can result from excessive vomiting.

Bicarbonate Buffer System

The primary blood buffer system governed by the equilibrium $H_2O + CO_2 \rightleftharpoons H_2CO_3 \rightleftharpoons H^+ + HCO_3^-$, regulated by lungs and kidneys.

Phosphate Buffer System

An intracellular buffering system operating via the equilibrium $H_2PO_4^- \rightleftharpoons HPO_4^{2-} + H^+$.

Amino Acid Buffer System

A buffering system where the amino group ($-NH_2$) accepts $H^+$ under acidic conditions forming $-NH_3^+$ and the carboxyl group ($-COOH$) releases $H^+$ under alkaline conditions forming $-COO^-$.

Carbohydrates

Polyhydroxy aldehydes, polyhydroxy ketones, or compounds that yield these substances upon hydrolysis.

Monosaccharides

Carbohydrates containing a single monomer unit that cannot be hydrolyzed into simpler carbohydrates, containing 3 to 7 carbon atoms.

Aldose

A monosaccharide containing an aldehyde group as its carbonyl functionality, such as glucose or glyceraldehyde.

Ketose

A monosaccharide containing a ketone group as its carbonyl functionality, such as ribulose or fructose.

Disaccharides

Carbohydrates composed of two monosaccharide units joined by a glycosidic bond, such as maltose, lactose, and sucrose.

Glycosidic Bond

A covalent linkage formed between the anomeric carbon atom of a carbohydrate and the hydroxyl group of another compound.

Cellulose

A primary structural homopolysaccharide of plant cell walls consisting of up to 15,000 glucose residues linked by $\beta(1 \rightarrow 4)$ glycosidic bonds.

Chitin

A structural homopolysaccharide composed of $\beta(1 \rightarrow 4)$ linked N-acetyl-D-glucosamine residues found in crustacean, insect, and spider exoskeletons.

Amylose

A linear form of starch making up 20% of its content, composed of several thousand $\alpha$-glucose units linked by $\alpha(1 \rightarrow 4)$ glycosidic bonds in a helical conformation.

Amylopectin

A branched form of starch making up 80% of its content, featuring $\alpha(1 \rightarrow 4)$ main chains with $\alpha(1 \rightarrow 6)$ branch points every 24–30 glucose residues.

Glycogen

The primary animal energy storage homopolysaccharide, containing $\alpha(1 \rightarrow 4)$ chains with frequent $\alpha(1 \rightarrow 6)$ branches every 8–14 glucose residues.

Glycosaminoglycans

Unbranched heteropolysaccharides in extracellular connective tissues composed of alternating uronic acid and hexosamine residues, also known as mucopolysaccharides.

Chondroitin Sulphate

A glycosaminoglycan made of glucuronate and N-acetyl galactosamine sulphate, serving as a structural component of cartilage used to treat osteoarthritis.

Heparin

A highly negatively charged glycosaminoglycan made of 2-sulphate-iduronate and N-sulpho glucosamine 6-sulphate that acts as an anticoagulant.

Keratan Sulphate

A glycosaminoglycan composed of galactose and N-acetyl glucosamine 6-sulphate found in cornea, bones, and cartilage that acts as a shock absorber.

Dermatan Sulphate

A glycosaminoglycan composed of glucuronate and N-acetyl galactosamine 4-sulphate located in skin, blood vessels, and heart tissue, participating in wound repair and coagulation.

Diabetes Mellitus

A medical condition characterized by persistent hyperglycemia and an inability to regulate blood sugar levels.

Type 1 Diabetes

An autoimmune form of diabetes in which insulin is no longer produced by the body, requiring insulin administration.

Type 2 Diabetes

A metabolic form of diabetes characterized by cellular insulin resistance, managed through lifestyle modifications.

Hyperglycemia

A physiological condition where blood sugar level is abnormally high, leading to excessive urination, dehydration, stiff blood vessels, nephropathy, and retinopathy.

Hypoglycemia

A physiological condition where blood glucose drops below $70\,mg/dL$, triggering fight-or-flight adrenaline release, sweating, headache, and dizziness.