MCAT Biology & Biochemistry Master Flashcards

Comprehensive set of 2000 Question and Answer cards based on the MCAT Biology & Biochemistry Master Study Guide.

According to the guide, what are the high-yield content review sections designed to help you master?

The Biology/Biochemistry section of the MCAT

What is the primary purpose of the 'MCAT Biology & Biochemistry Master Study Guide'?

To help master the Biological and Biochemical Foundations section through various high-yield strategies and review

What is the first ability tested in the Biological and Biochemical Foundations section?

Understanding biological systems

What is the second ability tested in the Biological and Biochemical Foundations section?

Applying biochemistry concepts

What is the third ability tested in the Biological and Biochemical Foundations section?

Analyzing experiments and data

What is the fourth ability tested in the Biological and Biochemical Foundations section?

Integrating concepts across disciplines

What is the fifth ability tested in the Biological and Biochemical Foundations section?

Reasoning scientifically under time pressure

What is the approximate percentage of Biochemistry in the MCAT Bio/Biochem section?

$$25\%$$

What is the approximate percentage of Biology in the MCAT Bio/Biochem section?

$$65\%$$

What is the approximate percentage of General Chemistry in the MCAT Bio/Biochem section?

$$5\%$$

What is the approximate percentage of Organic Chemistry in the MCAT Bio/Biochem section?

$$5\%$$

What are the seven identified High-Yield Concepts for Amino Acids & Proteins?

Structures, 1-letter and 3-letter abbreviations, Polarity, Charge at physiological pH, Acidic/basic side chains, Special properties, Hydrogen bonding, and Disulfide bonds

Which amino acid has the abbreviation Gly and G?

Glycine

What is the key feature of Glycine?

Smallest amino acid

Which amino acid has the abbreviation Ala and A?

Alanine

What is the key feature of Alanine?

Simple methyl group

Which amino acid has the abbreviation Val and V?

Valine

What is the key feature of Valine?

Branched side chain

Which amino acid has the abbreviation Leu and L?

Leucine

What is the key feature of Leucine?

Branched side chain

Which amino acid has the abbreviation Ile and I?

Isoleucine

What is the key feature of Isoleucine?

Branched side chain

Which amino acid has the abbreviation Met and M?

Methionine

What is the key feature of Methionine?

Sulfur-containing

Which amino acid has the abbreviation Pro and P?

Proline

What is the key feature of Proline?

Rigid ring

Which nonpolar amino acid is aromatic and has the abbreviation Phe or F?

Phenylalanine

Which nonpolar amino acid is aromatic and has the abbreviation Trp or W?

Tryptophan

What are the three nonpolar branched amino acids listed in the guide?

Valine, Leucine, and Isoleucine

List the two aromatic nonpolar amino acids.

Phenylalanine and Tryptophan

What is the feature of Serine?

Hydroxyl group

What is the feature of Threonine?

Hydroxyl group

What is the feature of Tyrosine?

Aromatic hydroxyl

What is the feature of Cysteine?

Thiol group

What is the feature of Asparagine?

Amide group

What is the feature of Glutamine?

Amide group

What are the two acidic amino acids?

Aspartate and Glutamate

What is the charge of Aspartate?

Negative

What is the charge of Glutamate?

Negative

What are the three basic amino acids mentioned?

Lysine, Arginine, and Histidine

What is the charge of Lysine?

Positive

What is the charge of Arginine?

Positive

What is the charge of Histidine?

Weakly positive

What is Step 1 in determining the net charge of lysine at physiological pH?

Identify Ionizable Groups

What ionizable groups are found in Lysine?

Amino group, Carboxyl group, and Basic side chain

What is Step 2 in determining the net charge of lysine at physiological pH?

Determine Charges at pH 7

What is the charge of Lysine's amino group at pH 7?

$$+1$$

What is the charge of Lysine's carboxyl group at pH 7?

$$-1$$

What is the charge of Lysine's side chain at pH 7?

$$+1$$

What is Step 3 in determining the net charge of lysine at physiological pH?

Add Charges: $(+1) + (-1) + (+1) = +1$

What is the final net charge of lysine at physiological pH?

$$+1$$

What is the definition of Primary Structure in proteins?

Amino acid sequence

What are the components of Secondary Structure?

Alpha helices and Beta sheets

What stabilizes the Secondary Structure of proteins?

Hydrogen bonds

What causes the 3D folding in Tertiary Structure?

Hydrophobic interactions, ionic interactions, hydrogen bonds, and disulfide bridges

What is the definition of Quaternary Structure?

Interaction between multiple protein subunits

What is a common example provided for Quaternary Structure?

Hemoglobin

How do enzymes affect the activation energy of a reaction?

They lower it

What is the effect of enzymes on the equilibrium of a reaction?

They do NOT change equilibrium

How do enzymes affect the reaction rate?

They increase reaction rate

What does it mean that enzymes are 'substrate-specific'?

They only catalyze specific reactions for certain substrates

In Michaelis-Menten kinetics, what does Vmax represent?

Maximum velocity

What does Km represent in Michaelis-Menten kinetics?

Substrate concentration at $1/2\,V_{max}$

What is kcat defined as?

Turnover number

If an enzyme has a low Km, what does that imply about its affinity?

High affinity

In competitive inhibition, what is the effect on Vmax?

Same (Unchanged)

In competitive inhibition, what is the effect on Km?

Increased

In noncompetitive inhibition, what is the effect on Vmax?

Decreased

In noncompetitive inhibition, what is the effect on Km?

Same (Unchanged)

In uncompetitive inhibition, what is the effect on Vmax?

Decreased

In uncompetitive inhibition, what is the effect on Km?

Decreased

What is Step 1 of understanding competitive inhibition?

Understand Mechanism: Competitive inhibitors compete for the active site

Why does Km increase in competitive inhibition (Step 2)?

More substrate is required to reach half-maximal velocity because of competition for the site

Why is Vmax same in competitive inhibition (Step 3)?

At very high substrate concentrations, the substrate outcompetes the inhibitor

What are the three main reasons ATP hydrolysis releases energy?

Relief of charge repulsion, resonance stabilization, and better solvation of products

What is the definition of Oxidation?

Loss of electrons

What is the definition of Reduction?

Gain of electrons

What is the mnemonic for Redox reactions?

OIL RIG (Oxidation Is Loss, Reduction Is Gain)

Where does Glycolysis occur in the cell?

Cytosol

What is the overall purpose of Glycolysis?

Convert glucose into pyruvate

What is the net yield of ATP per glucose in Glycolysis?

$2$ ATP net

What is the NADH yield per glucose in Glycolysis?

$2$ NADH

What is the pyruvate yield per glucose in Glycolysis?

$2$ pyruvate

Which enzyme converts Glucose to G6P in an irreversible step of Glycolysis?

Hexokinase

Which enzyme converts F6P to F1,6BP in Glycolysis?

PFK-1

Which enzyme converts PEP to Pyruvate in Glycolysis?

Pyruvate kinase

Which enzyme is the rate-limiting step of Glycolysis?

PFK-1

What two molecules activate PFK-1?

AMP and Fructose-2,6-bisphosphate

What two molecules inhibit PFK-1?

ATP and Citrate

In Step 1 of the 'High ATP cell' problem, what does high ATP signify?

A high-energy state

In Step 2 of the 'High ATP cell' problem, how does ATP affect PFK-1?

PFK-1 is inhibited by ATP

What is the final answer for how high ATP levels affect glycolysis?

Glycolysis decreases

Where does the Citric Acid Cycle (Krebs Cycle) occur?

Mitochondrial matrix

What is the NADH yield per acetyl-CoA in the Citric Acid Cycle?

$3$ NADH

What is the FADH2 yield per acetyl-CoA in the Citric Acid Cycle?

$1$ FADH_2$$

What is the GTP yield per acetyl-CoA in the Citric Acid Cycle?

$1$ GTP

What is the CO2 yield per acetyl-CoA in the Citric Acid Cycle?

$2$ CO_2$$

Where does the Electron Transport Chain (ETC) occur?

Inner mitochondrial membrane

What is the purpose of the Electron Transport Chain?

Generate ATP through oxidative phosphorylation

Which ETC complex does NOT perform proton pumping?

Complex II