MCAT Princeton Review Cards

Ribosome

Protein synthesis via translation

Nucleus

Houses the genome in chromosomes

Mitochondria

Cell respiration and energy production

Rough ER and Golgi

Protein trafficking and modification

Lysosome

Autophagy and degredation

Reversible Inhibition

Competitive inhibitors bind to active site; noncompetitive inhibitors to an allosteric site; uncompetitive inhibitors to the enzyme substrate complex

Glycolysis

Occurs in the cell cytoplasm; produces 2 net ATP, 2 pyruvate, and 2 NADH

Fermentation

Occurs in anaerobic comditions. Pyruvate is converted into lactic acid (in muscle) or ethanol (in yeast).

Repsiration

Occurs in aerobic conditions

Pyruvate decarboxylation

Pyruvate converted to Acetyl-CoA in the mitochondrial matrix

Citric Acid Cycle

Acetyl-CoA enters, reduced electron carries (NADH, FADH2) and CO2 exit

Electron Transport Chain

NADH/FADH2 oxidized, electrons passed from carrier to carrier, proton gradient generated across inner mitochondrial membrane

Oxidative Phosphorylation

Proton gradient provides energy for ATP synthase to phosphorylate ADP into ATP

Glycogenesis/Glycogenolysis

Occurs in the liver and skeletal muscle and is a means of storing/releasing glucose

Gluconeogenesis

Occurs in the liver when dietary glucose is unavailable and glycogen stores are depleted; conversion of non-carbohydrate precursors into glucose

Pentose Phosphate Pathway

Creates ribose-5 phosphate (precursor to nucleotide synthesis) and NADPH (reducing energy for other anabolic pathways)

Fatty Acid Oxidation

A repeated series of four reactions that liberate an acetyl-CoA in addition to generating FADH2 and NADH

Fatty Acid Synthesis

A repeated series of reactions that adds two carbons at a time until a 16-carbon fatty acid is produced. It requires NADPH.

Nucleic Acid

• Basic unit: nucleotide (sugar, nitrogenous base, phosphate)

• Sugar in DNA is deoxyribose; sugar in RNA is ribose

• 2 types of bases: double-ringed purines (adenine, guanine) and single-ringed pyrimidines (cytosine, thymine, uracil)

• DNA double helix; antiparallel strands joined by hydrogen bonding between base pairs (A=T, G=C)

• RNA is usually single-stranded: uses U not T

DNA Replication

Key enzymes are helicase (unwinds the DNA), primase (lays down RNA primer), amd DNA polymerases (synthesize DNA)

Point Mutation

One nucleotide is substituted by another; they are silent if the amino acid sequence doesn’t change

Frameshift Mutation

Insertions are deletions shift reading frame; generally serious mutations because many amino acids are affected

Operon

• An operator and promoter control transcription of one or more genes

• Generates polycistronic transcripts that are translated by polyribosomes

• Inducible systems need an inducer

Operator

Binding site of repressor protein

Promoter

Binding site of RNA polymerase

Transcription

Occurs on ribosomes in the cytoplasm

Post-translational Modifications

Made before the polypeptide becomes a functional protein, including disulfide bridge formation, glycosylation, phosphorylation, and clipping

Viruses

• Acellular structures of double or single-stranded DNA or RNA in a protein capsid

• Lytic Cycle: virus kills the host

• Lysogenic Cycle: virus enters host genome

• Retroviruses are RNA viruses that create DNA versions of themselves to insert in a host-cell genome

• Productive cycle: virus buds through cell membrane (animal virus only)

Bacteria

• Single-stranded prokaryotes

• Single circular DNA genome

• Gram+ have thick cell walls, Gram- have thin cell walls and an outer membrane

• Reproduce by binary fission

Prion

Abnormal protein that can induce structural changes in the normal version if the protein; responsible for spongiform encephalopathies

Law of Independent Assortment

• Alleles of unlinked genes assort independently in meiosis

• If both parents are Rr, the alleles separate to give the offspring a genotypic ratio if 1:2:1 (RR:Rr:rr) and a phenotypic ratio of 3:1 (dom:rec)

• For two traits: AbBb parents will produce AB, Ab, aB, and ab gametes

• The phenotypic ratio for an AbBb x AaBb cross is 9:3:3:1

Statistical Calculations

• The probability of A and B occurring together is the product of their individual probabilities (Prob A X Prob B)

• The probability of A or B occuring (assuming they are mutually exclusive) is the sum of their individual probabilities (Prob A + Prob B)

Action Potential

Signal generated by a neuron

Central Nervous System

Brain and spinal cord

Peripheral Nervous System

• Can be divided into the somatic (voluntary) and autonomic (involuntary divisions)

• The somatic system controls the skeletal muscles

• The autonomic system can be divided into the parasympathetic (rest and digest) division and the sympathetic (fight or flight) division

Arteries

Carry blood away from the heart

Capillaries p

The sites of exchange between blood and tissue

Blood Pressure

Directly proportional to cardiac output and peripheral resisitance

Respiratory System

Functions in gas exchange and pH regulation

Conduction Zone

For ventilation only and includes the nose, nasal cavity, pharynx, larnyx, trachea, right and left primary bronchi, bronchioles, and terminal bronchioles

Respiratory Zone

For respiration (gas exchange) and includes the respiratory bronchioles, the alveolar ducts, and the alveoli

Ventilation Rate

• Controlled by pH

• Reduced with a high pH and increases with a low pH

• Produce urine, regulate blood pressure, regulate ion and water balance, regulate pH, activate vitamin D, and secrete erythropoietin

• Functional unit is the nephron

Memory Cells

• Formed from B lymphocytes

• Remember antigen, speed up secondary response

Plasma Cells

• Formed from B lymphocytes

• Makes and releases antibodies (IgG, IgA, IgM, IgD, IgE), which induce antigen phagocytosis or inactivation

Cytotoxic T Cells

• Formed from T lymphocytes

• Destroy cells directly

Suppressor Cells

• Formed from T lymphocytes

• Regulate B cells and T cells to decrease anti-antigen activity

Helper T Cells

• Formed from T lymphocytes

• Activate B cells and T cells and macrophages by secreting lymphokines

Memory Cells

• Formed from T lymphocytes

• Remember antigen, speed up secondary response

Nonspecific Immune Response

Includes skin, passages lined with cilia, macrophages, acidic stomach and vagina, inflammatory response, and interferons (proteins that help prevent the spread of a virus)

Autoimmunity

Is when the immune system attacks and destroys normal body proteins

Follicle-stimulating Hormone

Follicle maturation (including estrogen and progesterone synthesis) spermatogensis

Luteinizing Hormone

Ovulation, testosterone synthesis

Adrenocorticotropic (ACTH)

Stimulates adrenal cortex

Thyroid-stimulating Hormone (TSH)

Stimulates thyroid gland

Prolactin

Milk production

Growth Hormone

Whole body growth, increases metabolism

Oxytocin

Uterine contraction, milk ejection

Antidiuretic (ADH, VASOPRESSIN)

Increases water retention

Thyroid Hormones (T4, T3)

Increase metabolism

Calcitonin

Decrease blood calcium

Parathyroid Hormone (PTH)

Increase blood calcium

Epinephrine

Increases “fight or flight” response

Insulin

Reduces blood sugar

Glucagon

Increases blood sugar

Cortisol

“Stress hormone” controls blood sugar, regulates metabolism, memory formation

Aldosterone

Increase renal sodium reabsorption

Testosterone

Male secondary sex characteristics

Estrogen

Female secondary sex characteristics, endometrial growth

Progesterone

Endometrial maintenance

Sarcomere

• Contractile unit of skeletal muscle

• Contains thick actin and thick myosin filaments

Skeletal Muscle Contraction

• ACh release from a neuron leads to action potential

• Ca²+ in the sarcoplasm increases

• Actin released from troponin/tropomyosin regulation

• Myosin and actin interact and cause muscle contraction

• Sarcomeres, H zone, and I band shorten

Alimentary Canal

• Mouth: grind food, begin starch digestion

• Esophagus: tube to stomach

• Stomach: storage tank, acid hydrolysis, limited digestion/absorption

• Small intestine: most digestion/asborption

• Large intestine: water reabsorption, store feces

Accessory Organs of the Digestive System

• Liver: make bile

• Gallbladder: store/concentrate bile

• Pancreas: secrete digestive enzymes and bicarbonate

Cell Division

• G1: cell growth and metabolism

• S: DNA replication

• G2: same as G1

• M: the cell divided in two

Cleavage

Mitotic divisions of the zygote to form the morula

Implantation

Blastocyst (trophoblast and inner cell mass) implants into the uterus wall

Gastrulation

Ectoderm, endoderm, and mesoderm form

Neurulation

Develop a nervous system and all other body organs

Society

The group of people who share a culture and live/interact with each other within a definable area

Socialization

The process through which people learn to be proficient and functional members of society

Norms

Are society’s rules and expectations for the behavior of its members and are enforced by sanctions

Formal Norms

(For example, laws) are generally written down, clearly defined, and accompanied by strict penalties for those who violate them

Informal Norms

(For example, how to behave at a funeral) are generally understood by al, but are less clearly defined, and carry no specific punishments for those who violate them

Mores

Are norms that are highly important for the benefit of society and are so often strictly enforced

Folkways

Are norms that are less important but shape everyday behavior (for example, styles of dress)

Taboos

Are norms that are so strong that their violation is considered forbidden and oftentimes punishable through formal or informal methods. Result in disgust toward the violator.

Non-normative Behavior

Challenges shared values and institutions, threatening social structure and cohesion. These behaviors are seen as abnormal and thus discouraged.

Deviance

Describes actions that violate dominant social norms, either formal or informal.

Assimilation

Occurs when an individual forsakes aspects of his or her own cultural tradition to adopt those of a different culture.

Amalgamation

Occurs when majority and minority groups combine to form a new group

Functionalism

Is a view that conceptualizes society as a living organism with many different parts and organs, each of which has a distinct purpose.

Conflict Theory

Views society as a competition for limited resources, which results in inequlaity

Symbolic Interactionism

Starts at the micro (close-up) level and sees society as a buildup of everyday typical interactions; it is therefore something that is constructed, not inherent

Feminist Theory

Is concerned with the differing social experiences of men and women, including how social structures contribute to gender differences (macro-level) and the effects of gender differences on individual interactions (micro-level)

Rational-choice and Social Exchange Theory

Both suggest that human behavior is driven by a desire to maximize benefit and minimize loss

Social Loafing

Tendency for people to exert less effort in a group than if they were individually accountable

Group Polarization

Phenomenon in which the average view of a member of a group is accentuated after like-minded group members confer