Chapter 3: Cells - The Living Units

Glycocalyx

Definite changes in the __________ of the cell membrane can be seen in a cell that is becoming cancerous.

Osmosis

Diffusion of a solvent, such as water, through a specific channel protein(aquaporin) or through lipid bilayer

secondary active transport

Driven indirectly by energy stored in concentration gradients of ions

membrane proteins

Make up half of the plasma membrane, all cell communication with environment, and most have specialized membrane proteins

desmosome

Mechanical couplings scattered like rivets along the sides of adjacent cells to prevent their separation

- lipid soluble and nonpolar substances - very small molecules that can pass through membrane or membrane channels - larger molecules assisted by carrier proteins

Molecules able to passively diffuse through membrane:

Fluid Mosaic

Specialized membrane proteins float through the plasma membrane, resulting in constantly changing patterns

Glycocalyx

Surface sugars form

Integral proteins

...

Peripheral proteins

...

hypotonic

A cell would plump with water and possibly lyse in which of the following solutions:

isotonic

A patient arrives in the hospital dehydrated. In order to fill his cells with fluid relatively quickly and no over-hydrate, what type of intravenous drip should he receive:

hypotonic

A solution that contains fewer solutes than the cell is:

Active processes

A way a substance crosses the membrane, energy(ATP) required

Passive processes

A way a substance crosses the membrane, with no energy(ATP) required

Gap Junctions

Adjacent cells held together by connexon proteins that form cylinders allowing ion flow between the cells' cytoplasm

receptor-mediated endocytosis

Cells of the body mainly use __________ for the selective endocytosis of most macromolecules.

mitochondria

The organelle that produces ATP from glucose is the __________.

Plasma membranes

These stop diffusion and create concentration gradients by acting as selectively permeable barriers

Generalized cell

This contains a plasma membrane, cytoplasm, and nucleus

phagocytosis and pinocytosis

Two types of endocytosis are:

nonpolar, hydrophobic lipid core of plasma membrane

What blocks most diffusion?

The pump must be phosphorylated

What critical event must occur before the sodium-potassium pump can transport sodium and potassium ions across the plasma membrane?

Cell size, shape, and subcellular components

What leads to differences in functions?

there is a transport maximum because transport proteins are required

When a molecule is transported via facilitated diffusion, ____________________.

filtration

Which of the following do NOT involve the movement of molecules from an area of greater concentration to an area of lower concentration:

facilitated diffusion and solute pumping

Which of the following processes require the use of protein carrier molecules:

Secondary active transport requires an input of energy, while facilitated diffusion does not.

Which of the following statements best describes the difference between facilitated diffusion and secondary active transport?

Osmosis leads to a volume change across the plasma membrane, while simple diffusion of a solute does not.

Which of the following statements best describes the difference between the simple diffusion of a solute and osmosis?

it allows water soluble molecules to pass through easily

Which one of the following is NOT true about the plasma membrane:

phagocytosis

Which transport process allows for the movement of solid particles across the plasma membrane?

Primary active transport

Which type of membrane transport process uses ATP as a source of energy?

cellular excretions

a class of extracellular fluid ex. saliva

integral protein

a membrane protein that functions in cell recognition

Plasma(cell) membrane

acts as an active barrier separating intracellular fluid from extracellular fluid - selectively permeable

Interstitial fluid

cells are submerged in this

Pinocytosis

endocytosis of a tiny quantity of extracellular fluid containing solute molecules

cerebrospinal fluid

fluid surrounding nervous system organs

Osmolarity

measure of total concentration of solute particles

cell junctions

membrane structures help to hold cells together through

Extracellular fluid

substances found outside cells Ex. blood plasma

Extracellular matrix

substances that act as glue to hold cells together

Exocytosis

the fusion of a vesicle with the plasma membrane to move substances out of the cell

tonicity

water concentration varies with # of solute particles because solute particles displace water molecules

gap junctions

Nutrients and ions can pass directly from cell to cell through special membrane junctions known as:

aquaporins

Osmosis transports water across membranes using:

require no ATP

Passive processes that move substances across membranes: