Final Exam Slide Deck

What are the three body fluid compartments?

Extracellular Fluid: 1/3 of the total water volume. It consist of interstitial fluid and blood plasma.

Interstitial Fluid: Extracellular Fluid that surround cells and between the cells

Blood Plasma: Liquid Matrix of blood and is found inside the circulatory system

Osmolarity

osmol/L the number of osmotically active particles

Hyperosmotic

When one solution has a higher concentration over another solution

Hyposmotic

When one solution has a lower concentration over another solution

Isosmotic

Equal concentrations within two solutions

Osmosis

The movement of water across a membrane in response to a solute concentration gradient

Passive Transport

Does not require an input of energy other than the potential energy stored in a concentration gradient

Active Transport

Requires outside energy such as ATP to move through a gradient

Concentration Gradient

A difference in the concentration of a substance between two places

Channel Protein

Create a water filled pore between the cell membrane

Carrier Protein

A protein that binds to a substrate they carry

Cotransporter

A carrier that moves more than one kind of molecule at a time

ATPase

Primary Active Transporters; also known as pumps are enzymes that hydrolyze for a designated purpose. An example could be to move molecules against their concentration gradient

Saturation

It’s a point where carrier transporters are filled with substrates and are working at their maximum rate

Endo/Exocystosis

Endo- a way for contents outside of the cell to enter

Exo- a way for contents inside the cell to exit

Electrochemical Gradient

A combination between an electrical and chemical gradient

Equilibrium Potential

The membrane potential that opposes the concentration gradient

Depolarize/Hyperpolarize

Depolarize-When the potential difference becomes more positive

Hyperpolarize-When the potential difference becomes more negative than the resting potential

Adult humans are what percentage of water?

45-60% water depending on age and sex

Osmolality of human body fluid is between the range of…

290-300mOsm

Water will move where…

where there is a higher osmolarity regardless of the concentration

What are examples of of molecules that can and cannot diffuse easily through a membrane?

Easy diffusion: Oxygen, Butyric Acid

Difficulty with passive diffusion: Glucose, Epinephrine, Insulin

What two factors are diffusion dependant on?

Lipid solubility and molecule size

What is the difference between simple diffusion and facilitated diffusion?

Facilitated diffusion uses a mediator called a mediated transport so that the molecule can move through the cell membrane.

Simple diffusion means the molecule can move through the membrane without the assistance of another molecule

What is the difference between simple/ facilitated diffusion and active transport?

Active transport requires energy such as ATP while simple/facilitated diffusion do not need energy

What is the difference between and channel protein and a carrier?

A carrier moves in and out of the cell with the protein while a channel stays within the membrane An example an ion channel is a water filled pore that can allow for specific ion to flow through. An example of a carrier proteins are GLUT carriers that move glucose across the membrane

Most ion channels are…

gated and apart of physiology

Glucose needs a…

carrier to cross a cell membrane via facilitated diffusion. Glucose is phosphorylated inside the cell so that the concentration gradient can pull glucose

The membrane potential=…

the voltage across the membrane; animal cells maintain an internally negative membrane potential

Recognize that Na, Cl, and K are…

Na and Cl are major extracellular ion. K is a major intracellular ion

Explain why the sodium equilibrium potential (E_Na) and the potassium equilibrium potential (E_K) are different?

The equilibrium potential for sodium differs from potassium because of their difference in permeability across the membrane and concentration. Specifically, because the membrane is more permeable for potassium to enter and exit the cell the resting membrane potential is closer to E_K.

Gap Junction

Tiny bridges between adjacent cells that keep cells together and allow for flow of electric and chemical signals

Hormone

• chemical signals/substances that act like messenger molecules in the body

• are secreted into blood by endocrine glands or cells and distributed all over the body by circulation

• only cells with the receptor for the hormone will activate a response

Neurotransmitter

• neurocrine molecule that diffuses from neuron across a narrow extracellular space to a target cell and has a rapid-onset effect

• chemicals/chemical signals secreted by neurons that diffuse across a small gap to the target cell

Receptor Protein

A protein located on the target cell that binds to a signal resulting in a response

Signal Transduction

When an extracellular signal molecule activates a membrane receptor that triggers an intracellular response

Second Messanger

Intracellular molecules that translate the first messenger into an intracellular response

Protein Kinase

Protein that adds a phosphate group to molecules

Protein Phosphatase

Protein that removes a phosphate group from a molecule

Receptor Channel or Ligand Gated Channel

A channel that opens in response to the the first messenger signal and opens up for the flow of the molecule across the membrane

G Protein Coupled Receptor ( GPCR)

a signal binding to a protein that results in a conformational change and secondary messenger signaling in the target

Receptor Enzyme

Membrane Proteins that bind to a signal on the extracellular side and activate enzymes on the intracellular side

Agonist

A competing ligand that binds and elicits a response

Antagonist

A competing ligand that binds and blocks a response

Antagonistic Control

Two neurons up and down regulating a system

Hormones and cytokines go all over the body, so why do they only work or cause a reaction in some cells?

Certain cells have a target receptor that allows for the hormone to bind and elicit a response

What is the difference between lipophilic and lipophobic signal molecules?

Lipophilic molecules can easily diffuse into the cell membrane and take a long time to respond. Lipophobic signals cannot enter the cell and therefore require a receptor or carrier to elicit a response. Lipophobic molecules elicit faster responses because it is amplified by second messengers within the cell

Explain how amplification can occur in a signal transduction pathway?

When a first messenger binds to a receptor , that can result in second messengers amplifying the signal within the cell causing a quicker effect