Cell Transport, Homeostasis, Biochemical Reactions, Enzymes, and Properties of Water

Flashcards covering cell transport mechanisms, homeostasis, biochemical reactions like cellular respiration and photosynthesis, enzyme functions, and the unique properties of water, including cohesion, adhesion, and its role as a solvent.

Passive Transport

Movement of substances across the plasma membrane without the use of the cell’s energy (with the concentration gradient).

Diffusion

Movement of substances across the plasma membrane from an area of high concentration to an area of low concentration.

Osmosis

Diffusion of water across the plasma membrane from areas of high concentration to areas of lower concentration.

Facilitated Transport

A carrier molecule aids in transporting a substance following the high-to-low concentration gradient.

Active Transport

Movement of solutes across the membrane. Requires the use of the cell’s energy & carrier molecules. Substances move from low concentration to an area of higher concentration (against the concentration gradient).

Endocytosis

Large particles are brought into the cell.

Exocytosis

Large particles leave the cell.

Homeostasis

Internal equilibrium; the plasma membrane regulates what enters and leaves the cell; a selectively permeable membrane only allows certain substances to pass through.

Hypotonic

Water moves in; cell bursts.

Hypertonic

Water moves out; cell shrivels.

Isotonic

No net movement; cell maintains equilibrium.

Cellular Respiration

Food molecules are converted to energy; there are three stages to cellular respiration; the first stage is called glycolysis and is anaerobic (no oxygen is required); the next two stages are called the citric acid cycle and the electron transport chain and are aerobic (oxygen is required).

Photosynthesis

Plant cells capture energy from the Sun and convert it into food (carbohydrates); plant cells then convert the carbohydrates into energy during cellular respiration; the ultimate source of energy for all living things is the Sun.

ATP

ATP is a molecule that stores and releases the energy in its bonds when the cell needs it; removing a phosphate group (P) releases energy for chemical reactions to occur in the cell and ATP becomes ADP; when the cell has energy, the energy is stored in the bond when the phosphate group is added to the ADP.

Fermentation

When cells are not provided with oxygen in a timely manner, this process occurs to continue producing ATP until oxygen is available again; glucose is broken down; there are two types of fermentation.

Enzymes

Povide energy to cells, build new cells, and aid in chemical processes. Break down complex molecules (substrate = reactant) and act as catalysts.

Aerobic Respiration

Requires oxygen to break down glucose, releasing energy to produce ATP. Efficient & occurs in most living things.

Anaerobic Respiration

Relatively slow breakdown of food without oxygen, producing a small amount of energy; often called fermentation.

Polar Molecule (Water)

Water molecule with opposite ends of the molecule with opposite charges.

Cohesion

Hydrogen bonds holds water molecules together.

Adhesion

Hydrogen bonds holds water molecules together.

Surface Tension

A measure of the force necessary to stretch or break the surface of a liquid. Related to cohesion.

Evaporative Cooling

The cooling of a surface occurs when the liquid evaporates.

Universal Solvent (Water)

Both solute and solvent; aqueous solution.

Active Transport

Movement of solutes across the membrane from low concentration to an area of higher concentration. Requires the use of the cell’s energy & carrier molecules.

Concentration Gradient

The gradual difference in concentration of solutes in a solution between two regions.

Carrier Molecules

Proteins in the cell membrane that bind and transport molecules using ATP.