Biological and Biochemical Foundations of Living Systems MCAT

aerobic respiration, PPP

viral infection could lead to an increase in which cellular pathways

basophils, eosinophils, neutrophils

Which cells are considered granulocytes?

mesoderm, ectoderm

The adrenal cortex is derived from the ______

The adrenal medulla is derived from the _____

lymphocytes, monocytes

Which cells are considered agranulocytes?

macrophages

Microglia in the CNS, Langerhans cells in the skin, and osteoclasts in the bone are examples of

CD4+ T cells respond to antigens presented on MHC-II which presents exogenous antigens

Why are CD4+ T cells most effective against bacterial, fungal, and parasitic infections?

glucagon, epinephrine, cortisol

three hormones that can raise blood glucose level

low blood glucose levels are immediately fatal, elevated glucose is harmless in the short term

Why does it make sense for having three different hormones that can raise blood glucose, while having only one hormone that can lower it

dendritic cells

what are the best antigen presenting cells?

decarboxylates pyruvate to acetyl coa

What does Pyruvate dehydrogenase do?

norepinephrine, epinephrine

Activation of the sympathetic NS results in the release of ____ from post-ganglionic neurons and _____ from the adrenal medulla

distal convoluted tubule

where does aldosterone regulate sodium reabsorption?

innate immunity

non-specific protection the body provides (e.g. tears, skin, complement system) is referred to as

MHC class I and II

Antigen Presenting Cells (APCs) express which proteins:

B-cells secreting antibodies

humoral immunity refers to:

to prevent regurgitation of blood into the atria while the ventricles are contracting

Why do the AV valves close at the beginning of systole?

nuclear localization signals

Nuclear proteins such as TFs require what in order to be in the nucleus?

target proteins to the secretory pathway

What do signal sequences do?

transduction

process whereby genes are transferred by a virus

anaphase II of meiosis II

sister chromatids separate during this stage

anaphase of mitosis

sister chromatids are pulled apart at the centromeres, each becoming an independent chromosome during this stage

anaphase I of meiosis

homologous pairs of chromosomes are separated into the two daughter cells

fats and carboxylic esters

lipases catalyze the hydrolysis of:

false

Inbreeding has an effect on the rate of spontaneous mutation, true or false

incidence of expression of deleterious recessive traits

Inbreeding can reduce the fitness of a population in the short term because it causes an increase in the:

cardiac output and resistance to blood flow

What are the two factors that normally determine the blood pressure?

SV X HR

cardiac output formula:

absorption of fats in small intestine, bile production, detoxification

Major functions of the liver:

True

Albumin has nothing to do with the immune response. True or False

sodium reabsorption by kidney tubules to decrease sodium secretion in urine

What does aldosterone do to sodium levels?

True

The liver can partially regenerate after illness or damage through mitosis. True or False

plasma membrane

In eukaryotes, oxidative phosphorylation occurs in the mitochondrion. The analogous structure used by bacteria to carry out oxidative phosphorylation is the:

kidney

Which organ is involved in regulation of all of the following: acid-base balance, blood pressure, water balance, and removal of nitrogen waste?

arteries, capillaries, veins (ACV)

order of blood flow

ribosomes

Radioactively labeled uracil is added to a culture of actively dividing mammalian cells. In which of the following cell structures will the uracil be incorporated?

G0, G1

A diploid nondividing cell is most likely in which stages?

parasympathetic motor fibers

The autonomic nerve fibers that directly innervate the heart to cause cardiac slowing are:

sodium and water

Physiologically normal kidneys respond to aldosterone by increasing the reabsorption of:

water absorption

What is the primary process that takes place in the colon (large intestine)?

by suppressing cells specific to the body's own antigens

How does the immune system avoid attacking the tissues of its own body?

T

Reuptake of calcium into the SR requires ATP hydrolysis. T or F

contraction

ACh induces ____ in skeletal muscle

lactate production

Pyruvate reduction by NADH leads to?

phospholipids, protein

E. coli cell membranes are comprised of predominately:

nuclei, tight junctions, bone-marrow derived

Characteristics of endothelial cells:

F

Platelets and mature RBCs have nuclei. T or F

phosphates

Histones interact with which DNA components?

liver

Where are blood clotting factors synthesized?

Tryptophan

What AA is the precursor to serotonin?

dehydrogenase

an enzyme belonging to the group of oxidoreductases that oxidizes a substrate by reducing an electron acceptor, usually NAD+/NADP+ or a flavin coenzyme such as FAD or FMN.

negative H, positive S

For which relative values of Delta H and S will a spontaneous rxn always occur?

aerobic, aerobic, anaerobic

CTA and ETC occur under ____ conditions, glycolysis occurs under ____ and ____ conditions

-(CH2)4NH2

lysine side chain

chemoreceptors

The cells of the macula densa are

baroreceptors

The juxtaglomerular cells are

epithelial cells throughout the nephron except the squamous cells of the thin ascending limb

where is the enzyme carbonic anhydrase found?

kidney, RBC synthesis in bone marrow

where is erythropoietin produced and what is its function?

blastopore

the anus is derived from the

acini

exocrine glands are composed of specialized epithelial cells organized into sacs called _____

pepsinogen (Chiefin makes me crave Pepsi)

what do the chief cells secrete

mucins, large glycoproteins formed mostly by carbohydrates.

what do goblet cells secrete?

gastric intrinsic factor

what do parietal cells secrete that is necessary for V12 absorption?

microtubules in 9+2 arrangement

describe the eukaryotic flagella arrangement

epithelium, submucosa, smooth muscle, serosa

sequence of layers moving from the inside of the GI tract lumen to the outside

colon, water absorption

The large intestine is know as the _____ and its main function is?

prevents reflux from stomach to esophagus

purpose of cardiac sphincter

parietal cells

epithelial cells that secrete hydrochloric acid (HCl) and intrinsic factor

acidic proteolysis (autocleavage)

Pepsinogen is converted to its active form pepsin via

CCK, secretin

the duodenum produces which hormones?

barr body

a small, densely staining structure in the cell nuclei of female mammals, consisting of a condensed, inactive X chromosome. It is regarded as diagnostic of genetic femaleness.

If a skeletal muscle is stimulated and a second stimulus is applied before relaxation is complete, a second contraction, which develops a greater tension, is fused to the first contraction. This is known as

summation

specialized immune cells that patrol the alveoli for foreign microbes

Alveolar macrophages

Surfacant functions to reduce

surface tension

How does fluid buildup by infectious pneumonia affect oxygen transport

oxygen diffusion into capillaries slowed

Which type of epithelial tissue would allows the highest rate of gas exchange in alveoli

simple squamous epithelium

_______ are proteins (5-20 kD) that do not cross the lipid bilayer and thus cannot enter the cytoplasm. Act on a receptor on the cell surface

Cytokines

Type I pneumocytes are involved with?

gas exchange between the alveoli and blood

Type II pneumocytes are involved with?

secretion of pulmonary surfacant

Injury to Type II pneumocytes would primarily cause

alveolar collapse

How many capillary beds must a red blood cell in the pulmonary artery pass before reaching the veins of the skin

2

A sympathetic antagonist would lead to

bronchi constriction

An acetylcholine antagonist is effectively the same as a

parasympathetic antagonist

ACE facilitates the conversion of angiotensin I into angiotensin II, which is a potent ______

vasoconstrictor

Both PTH and calcitriol increase

bone resorption

the deepest layer of the epidermis; undergoes mitosis to replace squamous epithelial skin cells that are damaged or worn out

Stratum basale

Layer of skin that contains all of the blood vessels, sensory receptors, hair follicles, and sweat glands that allow the skin to release excess heat and convey information about touch, temperature, pressure, and pain to the central nervous system

dermis

The blastula moves through the fallopian tube into the uterus where it burrows into the

endometrium

The adrenal cortex is derived from the ______, but the adrenal medulla is derived from the ______

mesoderm, ectoderm

The blastula implants in the endometrial lining and forms the

placenta

process initiated during fertilization by the release of cortical granules from the egg, which prevents polyspermy, the fusion of multiple sperm with one egg

Cortical reaction

In neurulation, or the development of the NS the neural tube becomes the _____ while the neural crest cells become the ____

CNS, PNS

what is the difference between pluripotent and totipotent cells?

totipotent cells can give rise to both the placenta and the embryo

stem cells that are able to differentiate into all three of the germ layers and their derivatives

pluripotent cells

_______ cells can give rise to all of the cell types that make up the body (e.g. embryonic stem). ______ cells can develop into more than one cell type, but are more limited

pluripotent, multipotent

signals that act on cells in the local area

paracrine

a type of cell / cell or cell / extracellular matrix signalling in multicellular organisms that requires close contact

juxtacrine

signals that act on distant tissues after traveling through the bloodstream

endocrine

what allows for cells to divide indefinitely and may even play a role in the survival of cancer cells

Telomerase

The umbilical arteries carry _____ blood with waste products while the umbilical vein carries _____ blood with nutrients

deoxygenated, oxygenated

There are two fetal shunts; one allows blood to enter the left atrium from the right atrium and another allows blood that still escapes to the right ventricle to bypass the pulmonary circulation, what are their respective names?

foramen ovale, ductus arteriosus