May 2025 Exam 1

Nerve impulses can occur because the sodium-potassium pump creates a

Resting membrane potential

In the plasma membrane of a neuron, which segment produces only graded potentials?

Receptive

Today my kids asked for ice cream, what type of receptors did they use while eating their sweet treat?

Chemoreceptor

What event stimulated the release of the synaptic vesicle?

Voltage gated Ca+ channels opening to allow Ca+ into the transmissive segment.

What is a graded potential?

Small, localized change in the resting membrane potential

What does the neurotransmitter bind to?

receptor on the postsynaptic membrane

What type of neuron would you find in the retina of the eye?

Bipolar

Sensory/afferent neurons are mostly what type of neuron.

Unipolar

What event must happen before an action potential can be generated?

Threshold must be met.

What glial cell produces cerebral spinal fluid?

Ependymal

What glial cell forms the blood brain barrier?

Astrocyte

What glial cell forms the myelin sheath in the PNS?

Schwann's cell

What glial cell cleans up cellular debris?

Microglia

Place the steps of myelination in order.

_1_ eventually the nucleus and cytoplasm are pushed to the periphery forming and neurolemma.
__2_ the Schwann's cell make contact with the axon.
_3__ the Schwann's cell wraps around the axon.
_4__ consecutive layers of the Schwann's cell encase the axon.

(Key) 2, 3, 4, 1

What Is the function of a Schwann's cell in an unmyelinated axon?

Protect and support.

Which of the following would be an action of the sympathetic nervous system?

Dilating the pupil

You are walking through the woods and see a bear. Your fight of flight kicks in. which division of the autonomic system is activated?

Sympathetic

You reach home safely without being harmed by the bear. You start to calm down. Which division of the autonomic nervous system is activated?

Parasympathetic

Which neurotransmitter is used to stimulate the sarcolemma?

Acetylcholine

What is the function of muscle tissue?

Contraction

which vitamin is necessary to get pyruvate into the citric acid cycle

vitamin A

study of how the structure of the human body function is called

physiology

basic unit of life

cell

what is matter

takes up space and has mass

a person's mass is the same whether they are on the earth or moon
true or false

true

a person's weight is the same whether they are on the earth or moon
true or false

false

mass is the amount of stuff inside an object
true or false

true

weight is the measurement of the gravitational pull on the object
true or false

true

electron has what charge

negative

proton has what charge

positive

neutron has what charge

neutral

atom like to have its outer most valance shell full of electrons
true or false

true

the ___ of radioisotopes is the amount of time it takes for half of the radioisotope to leave the body

biological half-life

chemical bond type is:
where two atoms with opposite charges

ionic

chemical bond type is:
where two atoms share and electron

covalent

chemical bond type is:
where the slightly negative end of a water molecule is weakly bound to the slightly end of another water molecule

hydrogen

when an unequal sharing of electrons occurs in a molecule. it makes one end slighlty positive and the other slightly negative. this molecule would be said to be

polar

when looking at the pH scale, which is considered neutral

6-8

when dissolved in water, ___ gives off hydrogen ions

acids

molecule that either picks up hydrogen ions or gives off hydroxide ions is known as ___

base

what is the building block of carbohydrate

monosaccharide

there are 20 different amino acids, which are the building blocks of

proteins

what is the building block of DNA

nucleotide

what is the building block of a lipid

fatty acid

plasma membrane is primarily comprised of

phospholipids

the plasma membrane is ___ which means that only certain things can cross it

selectively permeable

a cell that is place in solution that has higher concentration of particles. which way will the water flow

out of the cell

a cell that is placed in a hypotonic solution

gets bigger

cell in solution where the water equally moves in and out of the cell is in a ___ solution

isotonic

in diffusion particles move from an area of ___ to an area of ___

high concentration to low concentration

what is the resting membrane potential

the difference between the charge outside the cell and inside the cell

this type of cell junction acts as a spot weld, making it impossible for things to get in between the cells

tight junctions

which organelle synthesizes proteins

ribosomes

this organelle produces energy in the form of ATP

mitochondria

the organelle where DNA is found

nucleus

which organelle folds the proteins

rough endoplasmic reticulum

where does the citric acid cycle occur

mitochondria

electron transport chain occurs where

mitochondria

glycolysis occurs where

cytoplasm

which type of enzyme inhibition is it when a molecule that is not the ligand binds to the active site

non-competitive

an enzyme will ___ the energy needed to complete a reaction

increase

what are ways to regulate an enzyme

run out of substrate, phosphorylation, competitive inhibition

which stage does an enzyme become active

tertiary

which organelle modifies the proteins

golgi apparatus

the organelle that produces carbohydrates and lipids

smooth endoplasmic reticulum

during transcription, once the mRNA is attached to the ribosome, what is the next step

elongation

in protein formation, which protein is responsible for unzipping the DNA during transcription

DNA helicase

What is a target cell?

a cell that has specific receptors for a hormone

Which of the following functions solely as an endocrine gland?

A pituitary gland