The Plasma Membrane Vocabulary Flashcards

A set of 70 vocabulary flashcards covering concepts, definitions, components, and functions of the plasma membrane from lecture slides.

Cell membrane

The semipermeable boundary containing the cell and its components.

Plasma membrane

The barrier that separates the inside of a cell from the outside environment and controls what goes in and out.

Semi-permeable boundary

A boundary containing the cell and its components that selectively permits certain substances to pass while blocking others.

Fluid mosaic model

Describes the structure of the plasma membrane as a mosaic of components including phospholipids, cholesterol, proteins, glycoproteins, and glycolipids, resulting in a fluid character.

Homeostasis

A tendency to maintain a balanced or constant internal state; the regulation of any aspect of body chemistry, such as blood glucose, around a particular level.

Hydrophilic

Water loving.

Hydrophobic

Water fearing.

Phospholipid

A lipid that contains phosphorus and that is a structural component in cell membranes.

Phospholipid bilayer

A two-layered arrangement of phosphate and lipid molecules that forms a cell membrane, the hydrophobic lipid ends facing inward and the hydrophilic phosphate ends facing outward.

Polar molecule

A molecule with partial charges that mixes with water.

Receptor

A protein that detects a signal molecule and performs an action in response.

Selective permeability

A property of a plasma membrane that allows some substances to cross more easily than others.

Transport protein

A protein that moves substances or wastes through the plasma membrane.

Cellular barrier function

The action of the plasma membrane in separating the inside of a cell from the outside environment.

Main function of plasma membrane

To maintain homeostasis for the cell by keeping internal conditions stable.

Internal condition stability

The state of keeping internal conditions in an organism stable, which is necessary for survival.

Cellular level homeostasis

The required maintenance of stable internal conditions within each individual cell.

Organism survival dependence

The state wherein an organism's survival depends directly upon maintaining cellular homeostasis.

Surface polarity of bilayer

The property of the outer and inner surfaces of the phospholipid bilayer being polar.

Middle polarity of bilayer

The property of the interior center of the phospholipid bilayer being nonpolar.

Polar surface interaction

The interaction between the polar surface of the plasma membrane and watery environments.

Nonpolar middle function

Stops substances that are dissolved in water and forces those substances to pass through channels in the membrane.

Membrane channels

Structures in the plasma membrane through which water-dissolved substances must pass due to the nonpolar middle layer.

Glycerol head

The component of a phospholipid structure that forms part of the polar head group.

Fatty acid tails

Two nonpolar tails on a phospholipid that are attracted to each other and repel water.

Number of fatty acid tails

A phospholipid contains exactly 2 fatty acid tails.

Nonpolar tails

The hydrophobic lipid ends of phospholipids that face inward toward each other in the bilayer.

Phosphate group

A group attached in place of the third fatty acid tail in a phospholipid, making the head of the lipid more polar so it will bond with water.

Third fatty acid tail replacement

The substitution of a phosphate group in place of the third fatty acid tail found in standard lipid structures.

Polar head function

Bonds with water because the attached phosphate group increases its polarity.

Hydrophilic head group

The phosphate-containing head group of a phospholipid that faces outward and interacts with water.

Hydrophobic tails

The fatty acid tails of a phospholipid that face inward away from water.

Receptor proteins

Proteins situated amongst phospholipids that transmit signals for the cell.

Signal transmission

The function performed by receptor proteins when detecting chemical signals.

Anchor proteins

Proteins within the plasma membrane that provide internal structural support to give the cell shape.

Internal structural support

Support provided by anchor proteins to help maintain cell shape.

Cell shape regulation

The preservation of cell structure provided by anchor proteins.

Transport proteins function

Spanning the membrane to allow different types of substances or wastes to pass through.

Spanning the membrane

The arrangement of transport proteins extending completely across the phospholipid bilayer.

Cholesterol

A lipid component that helps prevent the fatty-acid tails of the bilayer from sticking together and helps strengthen the membrane.

Fatty-acid tails sticking prevention

A function of cholesterol located amongst the phospholipids in the bilayer.

Membrane strengthening component

Cholesterol, which helps strengthen the overall structure of the plasma membrane.

Carbohydrates in membrane

Molecules that serve as identity markers and help cells identify chemical signals.

Identity markers

Carbohydrate structures on the membrane surface that identify cells.

Chemical signal identification

The process by which carbohydrates on the membrane help cells recognize incoming chemical signals.

Glycoprotein

A membrane protein with a carbohydrate attached.

Glycolipid

A membrane lipid with a carbohydrate attached.

Peripheral membrane protein

A protein located on the surface edge of the plasma membrane.

Integral membrane protein

A protein integrated or embedded directly within the phospholipid bilayer.

Channel protein

A protein that forms a passageway across the membrane to regulate or allow substance movement.

Dynamic model

A characteristic of the fluid mosaic model describing a flexible membrane whose components are in constant motion.

Membrane flexibility

A key concept of the fluid mosaic model showing that the plasma membrane is non-rigid.

Phospholipid and protein movement

The concept that phospholipids and proteins are not held in one spot and are free to move around.

Boat on water analogy

An analogy describing how phospholipids and proteins move freely around the membrane surface.

Constant motion

The continuous movement of phospholipids, proteins, and other membrane components.

Semi-permeability

Another term for selective permeability, allowing some materials to cross while blocking others.

Import and export control

The regulation of specific molecules and ions entering and leaving the cell.

Size factor in crossing

A physical dimension property of a molecule that determines its ability to cross the plasma membrane.

Polarity factor in crossing

The charge property of a molecule that influences how easily it can pass through the membrane's nonpolar center.

Concentration factor in crossing

The relative abundance of a substance that affects its movement across the membrane.

Water ($H_2O$) transport

A molecule that can freely come and go across the plasma membrane as it pleases.

Carbon dioxide ($CO_2$) transport

A simple gas molecule that can pass across the membrane freely as it pleases.

Oxygen ($O_2$) transport

An essential gas molecule that can freely enter and exit across the membrane.

Ion transport regulation

The movement of charged ions regulated by membrane channels so they can enter only at certain times.

MS CCR Standards for Science 2018

The science curriculum standards defining learning objectives for studying cell membrane structure and transport.

Standard BIO.1C.1

Learning objective to develop and use models to explore how specialized structures within cells interact to carry out functions necessary for organism survival.

Standard BIO.1D.1

Learning objective to plan and conduct investigations to prove that the cell membrane is semi-permeable, allowing it to maintain homeostasis through transport processes.

Active transport processes

Processes noted in standard BIO.1D.1 used by the cell membrane to maintain homeostasis with its environment.

Passive transport processes

Transport mechanisms mentioned in standard BIO.1D.1 that assist in maintaining cellular homeostasis across a semi-permeable membrane.

Blood glucose regulation

A specific example of body chemistry regulated around a particular level to demonstrate homeostasis.