Human Anatomy & Physiology Sapling HW4- UNIT ONE

Examples of exocytosis.

- A single‑celled eukaryotic organism excretes digestive waste into the surrounding water. - A nerve cell releases peptides used as messengers into the extracellular space. - Proteins used as hormones are moved out of the cell in which they were manufactured.

Cell membrane's role in homeostasis

- If there is an excess of carbon dioxide inside the cell, some of the carbon dioxide molecules permeate the membrane and leave the cell. - Passive forms of transport move molecules such as water across the cell membrane with no energy added.

A protein allows Ca2+Ca2+ to flow into a mitochondrion when bound by a ligand.

uniporter

Facilitated diffusion is a type of passive transport that allows solutes to move across the plasma membrane of a cell. Describe facilitated diffusion

- Small, charged molecules and ions move down their concentration gradient out of a cell through proteins in the plasma membrane. - Solutes move across the membrane down their concentration gradient through specialized membrane proteins.

Which statements are properties of protein‑facilitated active transport?

- Substances move from an area of lower concentration to an area of higher concentration.' - The cell spends energy to move substances through a protein across the plasma membrane.

Phagocytosis

- cellular eating - large vesicles are formed - psuedopodia are used

Passive Transport

- does not require energy - moves substances from an area of high concentration to an area of lower concentration

Pinocytosis

- extracellular fluid is engulfed - tiny vesicles are formed

Identify the factors that affect membrane permeability.

- membrane thickness - temperature

Active Transport

- requires energy - moves substances from an area of low concentration to an area of higher concentration

The movement of ions through a membrane protein is an example of

active transport.

A protein moves one Ca2+Ca2+ out of the cell and three Na+Na+ into the cell.

antiporter

A protein moves one H+H+ ion and one K+K+ ion out of the cell.

symporter

Which is an advantage of a cell using the process of endocytosis to maintain homeostasis?

Large particles that cannot fit through the channel proteins can be brought into the cell and used.

Which choice describes diffusion?

The movement of a substance down a concentration gradient from an area of high concentration to an area of low concentration.

What is an aquaporin?

a membrane protein that contains a channel for water movement

What type of interactions cause proteins to fold into different shapes?

hydrogen bonds

Which of these are types of motor proteins?

myosin kinesin

Simple diffusion

movement of a solute out of the cell directly thru the plasma membrane

Secondary active transport

movement of one solute out of the cell, against its concentration gradient, via a cotransporter driven by another solute's gradient

Primary active transport

movement of solutes out of the cell against their concentration gradient using ATP-powered membrane pumps

Facilitated diffusion

movement of solutes out of the cell down their concentration gradient using ATP-powered membrane pumps

Facilitated diffusion is a protein‑facilitated movement of solutes across a membrane from an area of higher concentration to an area of lower concentration. Which of the terms best describes facilitated diffusion?

passive transport

What is clathrin?

peripheral membrane protein that mediates endocytosis

What is the term for the cellular ingestion of large particles or cells?

phagocytosis

Plasma membranes are selectively permeable, or semipermeable, meaning that

the membrane regulates what enters and leaves the cell.

Which example describes the use of symport transport across a membrane?

the transport of sodium ions along with amino acids into cells during digestion