MCAT Biology

Sympathetic Nervous System

carries signals that put your body on alert “fight or flight”

Parasympathetic Nervous System

carries signals to relax those systems

Increased urine production may be linked to…

hypertension and increased salt intake

The brain stem controls…

breathing, consciousness, heart rate, blood pressure, and sleep

The cerebellum controls…

muscle coordination

The hypothalamus controls…

body temp, heart rate, hunger, mood

What does an antidieuretic do?

A hormone that aids blood vessel constriction and helps the kidneys control teh amount of water and salt in the body. (Increases BP and kidneys make more urine)

What is the Glomerular Filtration Rate (GFR)?

Shows how well the kidney are filtering

Action potentials are caused by (depolarization/hyperpolarization)

depolarization. hyperpolarization inhibits action potentials

Mutations are heritable changes in the sequence of the nucleic acid component of:

a) chromosomes

b) nucleic envelope

c) ribosome

d) histone

a

Too much sodium can cause…

high blood pressure (hypertension)

What is aldosterone and what does it do?

steroid hormone produced by the adrenal cortex that regulates the balance of water and salts in the kidneys by reabsorbing Na+ and releasing potassium

What is/What happens in mitosis?

process where human body cells (not gametes) reproduce; a cell duplicates all of its contents, including its chromosomes, and splits to form two identical daughter cells.

The liver can partially regenerate due to

a) cell growth

b) fission

c) meiosis

d) mitosis

d

What is the role of albumin?

primary transporter plasma protein and helps to prevent fluid from leaking out of blood vessels and into other tissues

What is fission?

The splitting of a unicellular organism into two or more separate daughter cells

What is/What happens in meiosis?

type of cell division that reduces the number of chromosomes in the parent cell by half and produces four gamete cells.

(only occurs in sexually reproducing organisms)

In humans what is the self-replicating structure that contains DNA?

chromosome

Do humans have a cell wall?

NO. Only a cell membrane

What is the wavelength range of UV light?

100-400nm

What is teh wavelength range for visible light?

380-700nm

What is an autosome?

any chromosome that is not a sex chromosome

In which organelle of a eukaryotic cell is the pyrimidine uracil (UTP) incorporated into nucleic acid?

nucleus

What is derived from the embryonic mesoderm?

muscles, bone, blood vessels, and endocrine glands

The Krebs cycle is also known as the…?

TCA cycle

(True or False) The TCA cycle is anaerobic

False

Which organs break down glycogen?

The liver and (to a lesser extent) muscles

What does the pancreas produce?

insulin, glucagon, and other hormones

What does the liver break down and release?

glucagon and releases glucose

How does insulin decrease blood sugar (blood glucose) levels?

by facilitating the movement of glucose from the bloodstream into cells for energy

What does glucagon do?

increases blood glucose levels and therefore stimulates insulin secretion

What hormone triggers ovulation?

lutenizing hormone

What is the Loop of Henle?

part of the nephron in the kidneys which helps to reabsorb water and salt from the kidney tubules.

What are nephrons and what comprises them?

filtering units in the kidneys; comprised of filter (glomerulus) and a tubule.

What does the glomerulus and tubule do in a nephron?

the glomerulus filters blood and the tubule returns substances to the blood and removes waste

RNA polymerase II is only found in what type of organisms?

eukaryotes

The Shine-Dalgarno sequence is only found in what type of organisms?

prokaryotes

What is the border between intron and exon known as?

splice-acceptor site

Why does free energy NOT correlate with enzyme activity?

it is NOT a measure of reaction rate/activity

What is a nuclear localization sequence/signal?

an amino acid sequence that 'tags' a protein for import into the cell nucleus by nuclear transport

What are transcription factors?

proteins that help turn specific genes "on" or "off" by binding to nearby DNA; proteins that regulate the transcription of genes

the movement of ions or molecules across a cell membrane into a region of higher concentration, assisted by enzymes and requiring energy is known as what?

active transport

What does PKC do?

specifically phosphorylates substrates at serine/theronine residues

What do ABC transporters do?

they regulate the import and export of substances across plasma membranes

What is ATPase activity?

An enzyme’s ability to decompose ATP

cholesterol-rich domains within the membrane are known as what?

lipid rafts

True or False. “All enzymes are catalysts but Not all catalysts are enzymes”

True

What does high specificity mean in regard to an assay?

can distinguish one thing from many others;

specificity relates to the type of substrate for the reaction being catalyzed and not the quantity of substrate present in the cell.

Cells in what phase are not actively dividing?

Interphase

Nucleotides are linked to one another by phosphodiester bonds between the ___ base of one nucleotide and the ____________ group of the adjacent nucleotide in a way that the 5′ end bears a phosphate, and the 3′ end a hydroxyl group

sugar, phosphate

What do glucocorticoids do?

anti-infammatants in ALL tissue and control metabolism (in muscle, liver, bone and fat)

What is the endomembrane system?

portion of cells that are in charge of modifying proteins that will be secreted

What does insulin do?

helps blood sugar enter the body’s cells so it can be used for energy; therefore, insulin decreases blood glucose levels

In the chromatography of the reaction mixture, water absorbed on cellulose functioned as the stationary phase. What is the principal factor determining the migration of individual components in the sample?

hydrogen bonding

(solute concentration affects the size of spots on a paper chromatogram, not the average migration rate)

What is the formula for Rf value?

Rf = (distance travelled)/(distance to solvent front)

The functional group that represents a peptide bond is called a _______ group

amide

an enzyme stabalizes the _______ state; thus lowering the energy of activation

transition

glycolysis produces how many ATP per glucose?

2

Compunds that travel very far in TLC are more/less polar?

less polar

blood flows from arteries → _____ → ______

capillaries, veins