Biochemistry: Amino Acids, Proteins, and pH Lecture Notes

Flashcards covering amino acid types and structures, protein levels and functions, trace element roles and pathologies, and clinical acid-base interpretation based on the Biochemistry Study Guide.

Amino Acids

The smallest units, or building blocks, that make up proteins.

Essential Amino Acids

The 9 amino acids the body cannot make and must come from food: Histidine, Isoleucine, Leucine, Lysine, Methionine, Phenylalanine, Threonine, Tryptophan, and Valine.

Conditionally Essential Amino Acids

Amino acids that are normally made by the body but become essential during burns, trauma, severe illness, or rapid growth (e.g., Arginine, Tyrosine, Glutamine, Cysteine, Glycine, Proline).

R side chain

The component of the basic amino acid structure that determines which specific amino acid it is.

Primary Structure

The specific sequence of amino acids in a protein.

Secondary Structure

The protein structure level characterized by $\alpha\text{-helices}$ or $\beta\text{-sheets}$.

Tertiary Structure

The level of protein structure involving 3D folding to perform a specific job.

Quaternary Structure

The protein structure level involving multiple protein chains joined together, such as Hemoglobin.

Albumin

The most abundant plasma protein that maintains oncotic pressure and transports $T3$, $T4$, drugs, hormones, and calcium.

Prealbumin

A plasma protein used as a marker of nutrition; low levels indicate poor nutrition.

Alpha-1 Antitrypsin

An $\alpha_1$ globulin that stops neutrophil elastase from destroying the lungs; low levels lead to early emphysema or COPD.

Haptoglobin

An $\alpha_2$ globulin that binds free hemoglobin; levels decrease during intravascular hemolysis.

Transferrin

A $\beta$ globulin that acts as an iron transporter, often referred to as the "Iron Taxi."

Immunoglobulins

The $\gamma$ globulin fraction consisting of antibodies; levels increase during infection or multiple myeloma.

Zinc (Zn)

A trace element involved in the immune system, DNA synthesis, and wound healing; deficiency leads to poor healing and hair loss.

Copper (Cu)

A trace element critical for the nervous system and collagen; associated with Wilson disease (high levels) and Menkes (low levels).

Selenium (Se)

An antioxidant trace element that protects cells; deficiency causes cardiomyopathy, while high levels cause garlic breath.

Chromium (Cr)

A trace element that helps insulin work; deficiency causes poor glucose tolerance and neuropathy.

Lead (Pb)

A toxic element causing anemia and kidney damage; a key diagnostic board pearl is the presence of basophilic stippling.

Iron Deficiency Profile

A lab pattern showing low Iron, low Ferritin, High TIBC, and High Transferrin.

Normal Blood pH

The standard physiological range of $7.35 - 7.45$; levels below this indicate acidemia, and levels above indicate alkalemia.

Bicarbonate Buffer System

The most important buffer system in the body represented by the relationship $CO_2 + H_2O \rightleftharpoons H_2CO_3 \rightleftharpoons H^+ + HCO_3^-$.

Respiratory Acidosis

An acid-base disorder where the pH is low ($< 7.35$) and $PCO_2$ is high ($> 45\text{ mmHg}$), often caused by COPD.

Metabolic Acidosis

An acid-base disorder characterized by a low pH ($< 7.35$) and low $HCO_3$ levels ($< 22\text{ mmol/L}$).

Respiratory Alkalosis

An acid-base disorder caused by hyperventilation, resulting in a high pH ($> 7.45$) and low $PCO_2$ ($< 35\text{ mmHg}$).

Metabolic Alkalosis

An acid-base disorder often caused by vomiting, resulting in a high pH ($> 7.45$) and high $HCO_3$ ($> 26\text{ mmol/L}$).

Total Protein Reference Range

The normal range of protein in the blood, typically $6.5 - 8.3\text{ g/dL}$.