MCAT BIo

Kcat formula

kcat = vmax / [E] total

What graph shape does a cooperative process have?

Sigmoidal shape

Cells that continue though mitosis after maturation

epithelial cells (epidermis, gastrointestinal, respiratory), bone marrow stem cells, germ cells, fibroblasts

How many rings does a purine have

2 rings

Proteasome

ATP-dependent complex that selectively degrades ubiquinated proteins within a cell

Protease

Any enzyme that breaks down proteins into peptides or amino acids

What amino acids does phosphorylation typically happen?

serine, threonine, tyrosine

What amino acid residue does ubiquintation take place

Lysine

What is ubiquination?

A post translational modification to target protiens for location, signaling, or degradation

Charge of a protein that has an isoelectric point above physiological pH?

Negative -

What does detergent / SDS do?

1. Lyses bilayers by inserting itself

2. Extract lipids to lyse bilayers

Southern Blot

Targets DNA

Northern Blot

Targets RNA

Western Blot

Targets protiens

Prion

Misfolded variants of a protein that can cause misfolding when interacting with normally folded proteins of the same protein

Centrosome

A centrosome is the primary microtubule-organizing center & regulator of the cell cycle

Centromere

A section of non-coding DNA that is responsible for the movement of replicated chromosomes to daughter cells in mitosis / in the middle of the chromosome

Kinetochore

A structure on the centromere of a chromosome that acts as the attachment point for spindal microtubules mainly during mitosis / meiosis

Where are the variable regions of an antibody?

On the ends of the V

What is the cross-bridge cycle

The cycle calcium binding to troponin, exposing tropmyosin, exposing actin for myosin to bind, releasing ADP to form a power stroke

Cell Theory

1. All living things are made of cells

2. Basic functional unit of life

3. Cells come from pre existing cells

Endomembrane system pathway

DNA —> RNA —> Protiens (ribosomes) —> vesicles (golgi) —> membrane —> exocytosis —>

Epithelial Tissue

• Covers the body and lines cavities - involved with absorption and secretion

• the "parenchyma” (functional parts of tissue)

Endothelial Tissue

• Connective tissue / the framework

• extracellular matrix (collagen + elastin)

Types of Tissues

• Epithelial

• Endothelial

• Nervous

• Muscles

Bacteria Types

• Coccus / spherical (staph, s. aueus)

• Bacillus / rod shaped (e coli)

• Spital / helical (syphylsis)

3 Types of prokaryotic genetic recombination

1. transformation

2. conjugation

3. transduction

Transformation

A bacteria dies, other bacteria takes in its genetic material

Conjugation

Bacteria sex; F- becomes F+; F+ has the conjugation bridge

Transduction

Genetic info comes from a virus

Retrovirus

Uses reverse transcriptase and their RNA to produce DNA to highjack cells

What types of cells don’t replicate

Heart cells and neurons

G1 phase

Increases size of the cell; checkpoint before S phase to ensure proper DNA

S Phase

Replicates genetic material; each cell has 46 chromosomes at this point

G2

Nucleus dissolves & final growth / checkpoint before mitosis

Steroid Hormones

Cholesterol derivative; 4 ringed structures; mainly non-polar (ends in oid, ol, one)

Amino acid hormones

Very polar; must bind to a receptor because it can’t pass through membranes; causes signal transduction cascades

Peptide hormones

Polar and protein-derived hormones (ex. insulin) - need to bind to a receptor

Heart electrical pathway

SA node —> AV node —> Bundle of His —> Purkinjie fibers

Explain the electrical conduction

1. SA node fires

2. AP spreading across both atria causes contraction (atrial kick)

3. Reaches the AV node

4. AP swiftly travels down the interventricular septum, wrapping around the ventricular walls

How does the heart pump

1. Blood drains into the ventricles follwoing passive opening of TV/BV

2. SA node fires

3. AV node delay

4. Ventricles depolarize

5. Ventricles contract opening the aortic and pulmonary vlaves pushing blood out of the heart

6. ventricles repolarize and relax

Mean arterial pressure formula

MAP = Cardiac output (HR x SV) x system vascular resistance

Oncontic pressure formula

ii = imRT

What causes high osmotic pressure?

Higher concentration of solutes = higher osmotic pressure

What is formed by the ectoderm?

epidermis, hair, epithelium of nose, mouth, lower anal canal, lens of the eye, inner ear, adrenal medulla, nervous system

What is formed by the mesoderm?

musculoskeletal system, circulatory system, excretory system, gonads, connective tissue of digestive and respiratory systems, adrenal cortex

What is formed by the endoderm?

epithelium of digestive and respiratory systems, pancreas, thyroid, bladder, distal urinary tract, liver

Products of PPP oxidative phase

NADPH, CO2

Products of PPP non oxidative phase

Ribose-5-Phosphate, fructose-6-phosphate

How much ATP does 1 glucose molecule make during aerobic respiration?

30-32 ATP

Net products of glycolysis (1 unit of glucose)

• 2 ATP

• 2 NADH

• 2 Pyruvate / Acetyl CoA

Net products of CAC (1 Acetyl CoA)

• 3 NADH

• 1 FADH2

• 1 ATP / GTP

When is insulin released and what happens when it is?

• release with high BGL

• when released it promotes glycogenesis and increases glycogen synthesis and storage

When is glucagon released and what happens when it is?

• released with low BGL

• when released it promotes glycolysis and causes glycogen to be turned into glucose

Can acetyl-CoA from fatty acids be used in the CAC

NO!

Why are triglycerides good for energy storage?

1. energy-rich

2. inert (no random rxns)

3. no functional roles

4. very hydrophobic (not weighed down by water)

What limb of in the loop of Henele is permeable to water

descending limb

When is the glucose and amino acids reabsorbed in the renal system

Proximal convoluted tubule

Oxidoreductase

Transferes electrons from one molecule to another (Dehydrogenases, Cytochrome)

Transferases

Transfers functional groups between molecules (all kinases, phoshorylase)

Hydrolases

Uses water to break bonds (decarboxylase, phosphatases, GTPase, protease)

Lyases

Break bonds through means other than the addition of water (isomerases, mutases)

Ligases

Joins two large molecules together by forming a new chemical bond (DNA ligase)

Convergent Evolution

When unrelated species develop similar traits due to similar environements

Divergent Evolution

Related species branch out and develop different traits due to different pressures, often leading to speciation. This produces homologous structures

Parallel Evolution

Related species evolving similar traits independently

Hardy weinberg equilbirum

p²+2pq+q²=1

p+q=1

What is another name for complex II of the ETC

Succinate Dehydrogenase

Genomic Imprinting

The process by which only one copy of a gene in an individual (either from their mother or father) is expressed while the other copy is suppressed.

Osteoblasts

Builds bones / bone marrow

Osteoclasts

Breaks down old or damaged bone and does bone resorption

How can inbreeding effect the population?

It can increase the incidence of expression of deleterious recessive traits

Phosphorylase

Adds phosphate groups

Phosphotase

Removes phosphate groups

Kinase

Transfers phosphate group from ATP to other molecules

Cytochrome

A redox-active protein that it’s primary function is to be an electron transporter

During phosphorylation the phosphate group be exchanged for an H or an O atom?

H atom. Will bind to the O

Where does fatty acid oxidation take place?

The mitochondria

Where does fatty acid synthesis take place

Cytosol

What gets added to Acetyl-CoA to make Malonyl-CoA

A carboxylic acid

What decreases O2 affinity for hemoglobin?

1. Increased CO2

2. Decreased pH (acidosis)

3. Increased temperature

4. Increased 2,3-BPG

Henry’s Law

Higher pressure of a gas above a liquid means more gas will dissolve into the liquid (S=k*p)

What does microRNA do?

They are post-transcriptional regulators of gene expression that bind to RNA, which leads to mRNA degradation, destabilization, or translational inhibition effectively “silencing” genes

Native PAGE

Separates molecules based on their electrophoretic mobility relying on length, confirmation, and charge

Gel filtration chromatography

Separates proteins only on the basis of size

Ion exchange chromatography

Separation of molecules based on their charge

Isoelectric focusing

Separates molecules based on their isoelectric points

B cells

A lymphocyte developed in the bone marrow that produces antibodies

Helper T cells (CD4+)

Activated by antigens presented on Class II MHC receptors and they secerete cytokines that activate other cells (B cells and killer T cells) and initiate the adaptive immune system

Killer T cells (CD8+)

Activated by antigens associated with Class I MHC receptors present on nucleated cells in the body, and upon activation they release cytoxoic granules that induce apoptosis in target cells

Microglia

The central nervous system (brain’s) specialized macrophages

Macrophages

Part of the innate immune system, they engulf pathogens, digest them, and present antigens on the MHC. They also release cytokines that cause inflammation and attract more immune cells

Desmosomes

Intercellular junctions that function as anchors to from strong sheets of cells

Gap Junctions

Intercellular junctions that provide cytoplasmic channels between adjacent cells

Intercalated discs

Specialized intercellular junctions between cardiac muscle that provide direct electrical coupling among cells

Tight Junctions

Intercellular junctions that prevent the movement of solute within the space between adjacent cells

vmax decrased

km not affected

Noncompetitive Inhibition

Vmax increased

Km increased

Uncompetitive Inhibition

Vmax not affected

Km increased

Competitive inhibition

Steady state assumptions

1. Solutions are behaving ideally

2. Constants remain constant

3. Substrate to product reaction that occurs without enzyme is negaligable