Cell membrane and transport test

based on study guide and notes

Passive Transport

A process that does not require energy input as substances move along their concentration gradient.

Active Transport

A process that requires energy (ATP) to move substances against their concentration gradient.

Endocytosis

The process of engulfing substances into the cell via vesicle formation.

Exocytosis

The process by which vesicles fuse with the plasma membrane to release substances outside of the cell.

Phospholipids

Integral components of cell membranes that form a bilayer, providing structural stability and selectively allowing substances to pass.

Fluid Mosaic Model

A model describing the structure of the cell membrane as a mosaic of various components that move laterally, contributing to flexibility and functionality.

Permeability

The ability of a membrane to let substances through; membranes can be semi-permeable or selectively permeable.

Integral Proteins

Proteins that span the entire lipid bilayer and facilitate transport by acting as channels or carriers.

Peripheral Proteins

Proteins attached to the exterior or interior surfaces of the membrane, involved in signaling and providing structural support.

Glycolipid

A carbohydrate attached to a lipid that plays a key role in cell recognition and signaling.

Extracellular Fluid (ECF)

The fluid that exists outside the cell.

RNA

The intermediate molecule that carries the genetic information from DNA and serves as a template for protein synthesis.

t-RNA

The molecule that transfers specific amino acids to the ribosome during protein synthesis, matching them with the corresponding codons on the mRNA.

m-RNA

The molecule that carries the genetic code from DNA to the ribosome, where it is translated into a specific sequence of amino acids to form proteins.

Amylase

An enzyme in saliva that breaks down amylose (starch) into maltose.

Peristalsis

The rhythmic contraction of muscles in the digestive tract that moves food along, aiding in the process of digestion and subsequent absorption of nutrients.

Gastric Juice

A mixture of hydrochloric acid, digestive enzymes, and mucus that aids in digestion in the stomach, particularly in breaking down proteins.

Accessory Organs

Organs that aid in digestion but are not part of the digestive tract itself, including the liver, pancreas, and gallbladder.

Liver Functions

Includes glycogen storage, drug detoxification, bile production, and red blood cell breakdown.

Pancreas

Produces digestive enzymes that aid in the digestion of food.

Gallbladder

Releases bile to aid in the digestion of fats.

Carbohydrate Digestion

Begins in the mouth, where saliva containing amylase breaks down carbohydrates.

Digestion Process

Mouth → pharynx → esophagus → stomach → small intestine → large intestine → anus.

Channel protein

Allows a particular molecule or ion to cross the plasma membrane freely, mostly open and very specific.

Carrier protein

Changes shape to transport some molecule, using energy from ATP, and interacts selectively with a specific molecule to aid its movement across the membrane.

Cell Recognition Protein

A glycoprotein that has a carbohydrate chain; alerts the immune system to potential invaders.

Receptor protein

Shaped for specific molecules to bind, triggering responses within the cell.

Enzymatic Protein

Actual enzymes embedded in cell membranes.

Junction Protein

Forms connections between adjacent cells, maintaining tissue integrity and communication.

Diffusion

The movement of molecules from high to low concentration, enabling passive crossing of the plasma membrane without energy.

Passive transport

Transport method that does not require energy, including diffusion, facilitated diffusion, and osmosis.

Active transport

Transport method that requires energy to move substances against their concentration gradient.

Osmosis

Diffusion of water through a selectively permeable membrane.

Hypotonic Solution

A solution with a lower concentration of solutes than inside the cell, leading to water movement into the cell.

Exocytosis

Process by which cells expel internal substances.

Endocytosis

Process by which cells engulf external substances.

Phagocytosis

A type of endocytosis where the cell engulfs solid particles (cell eating).

Pinocytosis

A type of endocytosis where the cell engulfs liquid substances (cell drinking).

Enzyme

A biological catalyst that accelerates chemical reactions in living organisms by lowering the activation energy required.

Amylase

An enzyme that breaks down carbohydrates.

Lipase

An enzyme that breaks down lipids.

Pepsin and Trypsin

Enzymes that break down proteins.

Active Site

The specific region on an enzyme where the substrate binds.

Substrate

The substance that an enzyme works on.

Enzyme-Substrate Complex

The intermediate formed when a substrate binds to an enzyme at the active site.

Induced Fit

A model describing how an enzyme changes shape slightly to fit the substrate perfectly.

Synthase

An enzyme that catalyzes the synthesis of complex molecules from simpler ones.

Hydrolase

An enzyme that catalyzes the hydrolysis of chemical bonds.

Co-factors

Non-organic, non-protein chemical compounds that assist enzymes during the catalysis of reactions.

Co-enzymes

Organic compounds that help enzymes by acting as carriers for chemical groups or electrons.

Competitive Inhibitors

Substances that bind to the active site and block the substrate from binding.

Allosteric Site

An alternative site on an enzyme, distinct from the active site.

Inhibitors

Substances that block enzyme reactions.

Feedback Inhibition

A cellular control mechanism where the end product of a metabolic pathway inhibits an enzyme involved in an earlier step.

Denatured Enzyme

An enzyme that has lost its functionality due to alteration of its structure.

Cell membrane

Phospholipid and protein covering of every cell, controls what goes in and out of each cell

diffusion

Movement from high to low concentration

concentration gradient

the difference in concentration between two regions

solute

the solid that is dissolved in a solution

solvent

The liquid that dissolves the solute in a solution

Osmotic pressure

the pressure of water moving across membranes caused by a concentration gradient

Isotonic solution

solution that has the same concentration inside and outside of it

hypertonic solution

solution that has a greater concentration of solute as the cell is surrounds, will cause cell to shrink

Hypotonic solution

solution that has lesser concentration of solute as the cells it surrounds. will cause cells to burst

plasmolysis

shrinking of a plant cell due to being placed in a hypertonic solution

turgor pressure

hydrostatic pressure due to a plant cell being placed in Hypotonic solution. is pressure on inside of plant cell against the cell wall

facilitated transport

the process of moving molecules across a cell membrane via specific transmembrane proteins, without the use of energy.

crenation

the process in which red blood cells shrink due to being placed in a hypertonic solution.

active transport

the process of moving molecules across a cell membrane against their concentration gradient, requiring energy in the form of ATP.

endocytosis

cells bringing in materials by forming vesicle around substance outside the cell with the cell membrane

vesicle

A small membrane-bound sac used for transporting substances within or outside a cell.

phagocytosis

A type of endocytosis where cells engulf large particles or microorganisms by wrapping around them and forming a vesicle.

exocytosis

opposite if endocytosis. Vesicle inside cell fuses with cell membrane, depositing contents on the outside

glycolipid

carbohydrate attached to phospholipid on cell membrane. often serves in cell identification and communitcation

Fluid Mosaic Model

current model of membrane structure. A phospholipid fluid sea is embedded with a wide variety of protein molecules.

pinocytosis

“cell drinking” process by which cells engulf liquid and small particles from the surrounding environment.