AP Bio Chapter 7

The membrane at the boundary of every cell that acts as a selective barrier, thereby regulating the cell’s chemical composition

The currently accepted model of cell membrane structure, which envisions the membrane as a mosaic of individually inserted protein molecules drifting laterally in a fluid bilayer of phospholipids.

A molecule that is a constituent of the inner bilayer of biological membranes, having a polar, hydrophilic head and a nonpolar, hydrophobic tail.

A type of lipid characterized by a carbon skeleton consisting of four rings with various functional groups attached.

The plasma membrane is commonly described as a _____.
Why???

Its component proteins and phospholipid molecules can move about, causing the membrane to be what??

The phospholipids in a membrane form a two-layer framework called a _____. The steroid _____ helps stabilize the phospholipids. ______ are attached to some of the molecules that make up the membrane.

The ____________ of the bilayer is one reason membranes are selectively permeable.

Having an aversion to water; tending to coalesce and form droplets in water.

_________-- those that are soluble in lipids-- can easily pass through the membrane.

In addition, what can small molecules like O2 do?

__ __ (like water and glucose) and ___ (such as sodium ions and hydrogen ions) cannot pass directly through the phospholipids of the plasma membrane. They must pass through specific __ ___ ___

A transport protein in the plasma membrane forms a ___ through which water molecules or a specific solute can pass.

Diffusion is the tendency for particles to move down their ____.

The diffusion of a substance across a biological membrane.

The diffusion of water across a selectively permeable membrane.

In comparing two solutions, referring to the one with a greater solute concentration, causing the cell to shrink

Having the same solute concentration as another solution, resulting in neither shrinking nor swelling of the cell

In comparing two solutions, referring to the one with a lower solute concentration, causing the cell to swell.

If water is not removed from an animal cell, what will happen to it?

What prevents a plant cell from bursting?
What is the desired effect of the plant?

What occurs when a plant cell wall is exposed to a hypertonic environment?

The spontaneous passage of molecules and ions, bound to specific carrier proteins, across a biological membrane down their concentration gradients.

A property of biological membranes that allows some substances to cross more easily than others.

Facilitated diffusion is a type of __ __, since the molecules are diffusing through the membrane and the cell expends no energy to move them.

Sometimes a cell needs to move a solute against its concentration gradient. This process is called __ __, and it requires input of energy from __.

The movement of a substance across a biological membrane against its concentration or electrochemical gradient with the help of energy input and specific transport proteins.

An adenine-containing nucleoside triphosphate that releases free energy when its phosphate bonds are hydrolyzed. This energy is used to drive endergonic reactions in cells.

How does ATP play a part in active transport?

The cellular uptake of macromolecules and particulate substances by localized regions of the plasma membrane that surround the substance and pinch off to form an intracellular vesicle.

The cellular secretion of macromolecules by the fusion of vesicles with the plasma membrane.

__ and __ are processes allow patches of membrane to flow from compartment to compartment, reminding us that a cell is a dynamic structure.

___ is the movement of intracellular vesicles to the plasma membrane, where they fuse with the membrane and release their contents into the surrounding fluid. This process occurs predominantly in __ __, such as mucus-producing cells or pancreatic cells, that secrete enzymes into the digestive tract.

In endocytosis, membranes ___, or pinch in, to form a vesicle, moving the enclosed materials inside the cell. This process can take different forms, each involving its own specific cell machinery.

A type of endocytosis involving large, particulate substances, accomplished mainly by macrophages, neutrophils, and dendritic cells.

In __, or "cell eating," the cell engulfs debris, bacteria, or other sizable objects.

__ produces a __, which usually fuses with one or more __ containing hydrolytic enzymes. Materials in the vacuole are broken down by these enzymes and degraded.

A type of endocytosis in which the cell ingests extracellular fluid and its dissolved solutes.

In __, or "cell drinking," the cell engulfs extracellular fluid, including molecules such as sugars and proteins. These materials enter the cell inside a __. Epithelial cells in capillaries use this to engulf the liquid portion of blood at the capillary surface. The resulting vesicles travel across the capillary cells and release their contents to surrounding tissues, while blood cells remain in the blood.

The movement of specific molecules into a cell by the inward budding of membranous vesicles containing proteins with receptor sites specific to the molecules being taken in; enables a cell to acquire bulk quantities of specific substances.

___ is very specific. It is triggered when membrane receptors bind to specific external molecules, such as protein-cholesterol complexes or proteins bound to iron. Membrane vesicles pinch off, and the external protein and its cargo are brought into the cell.

___ is very specific. It is triggered when membrane receptors bind to specific external molecules, such as protein-cholesterol complexes or proteins bound to iron. Membrane vesicles pinch off, and the external protein and its cargo are brought into the cell.

___ is very specific. It is triggered when membrane receptors bind to specific external molecules, such as protein-cholesterol complexes or proteins bound to iron. Membrane vesicles pinch off, and the external protein and its cargo are brought into the cell.

___ is very specific. It is triggered when membrane receptors bind to specific external molecules, such as protein-cholesterol complexes or proteins bound to iron. Membrane vesicles pinch off, and the external protein and its cargo are brought into the cell.

Which process is responsible for the uptake of iron in human cell?