AP Biology: Unit 2 Terms

Homeostasis

The maintaining of an internal environment so that an organism can function

Normal range for PH

5.5-7

The 3 claims of Cell theory

1. All organisms are made up of cells

2. The cell is the fundamental unit of life

3. Cells come from pre-existing cells

Metabolism

The entire set of chemical reactions by which cells transfer energy from one form to another and build and break down molecules

A cell that uses it’s structure to help with it’s function

Red blood cells → Due to its distinct cave shape, it’s able to be more flexible and can pass through narrow blood vessles with diameters smaller than that of the cell itself

Endomembrane System

System that will procuce membrane:

Nuclear envelope

Endoplasmic reticulum

Golgi apparatus

Vesicle

Cell Membrane

Nuclear envelope

The boundry of the nucleus

Endoplasmic reticulum

An organelle that is involved in the production of proteins and lipids

Rough ER

Studded with ribosomes, which build proteins

Smooth ER

Makes Carbs and lipids

Golgi Apparatus

Modifies and sorts proteins and lipids produced by the ER

Vesicle

membrane ball that transports things

Lysosome

Degrade damaged or unneeded macromolecules (Type of vesicle)

Cell Membrane

Exterior of the Cell

Chloroplast

A plastid that conains chlorophyll and in which photosynthesis takes place

Chlorophyll

The green pigment that plants use to make food during photosynthesis

Photosynthesis

Process where plants, algae, and some bacteria use sunlight, water, and carbon dioxide to create their own food (glucose) for energy and growth

Mitochondria

The powerhouse of the cell, an essential double-membraned organelle in eukaeyotic cells

Similarities between mitochondria and chloroplasts

• Double membrane

  • Includes outer membrane which matches the construction of a eurkaryotic membrane

  • Inner matches composition of prokaryotic membrane

• Both harness energy

• Both have enclosed interconnected compartments

• Do some cellular energy

  • Chloroplast does photosynthesis

    • Creates glucose

  • Mitochondria uses glucose and other things to make ATP

Cytoskeleton

System of protein filaments that provide internal support for the cells

Amphipathic molecules

Have both hyrophobic and Hydrophilic parts

Phospholipids

Essential, amphipathic lipid molecules that form the fundamental structure of all cell membranes, creating a protectve, semi permeable barrier

Peripheral proteins

Bound to the surgace of the membrane (corner)

Integral proteins

Penetrate the hydrophobic core

Transmembrane proteins

Protein that goes through the membrane from one sie to the other, spans the membrane

Diffusion

As particles move from areas of higher concentration to areas of lower concentration

Aquaporins

Channel proteins that facillitate the passage of water

Dynamic equillibrium

Molecules cross the membrane at the smae rate both directions

Active Transport

Movement of particles with the use of ATP (From low to high concentration)

Passive transport

Movement of particles without the use of energy

Osmosis

Diffusion of water across a selectively permeable membrane

• Water dilutes things

• Water (solvent): Low → High concentrations of solute

• Water moves High → Low

Tonicity

Surrouinding solution causes a cell to gain or lose water

Isotonic

Solute concentration is the same as inside the cell (no net water movement)

• Animal: like to be isotonic

• Plants: need more water

Hypertonic: Solute Concentration is higher than in the cell (Cell loses water and shrinks)

• Animal gets dehydrated, eventually gets back to normal

• Plant: Cell membrane will tear away from cell wall and kill it

Hypotonic: Solute concentration is lower than inside the cell (Cells gains water and swells)

• Animal: More likely to pop

• Plant cells thrive

Facilitated transport

When material moves across the plasma membrane with the assistance of transmembrane proteins down a concetration gradient without using cellular energy

Osmolarity

Total amount of solutes dissolved in a specific amount of solution (hypotonic, isotonic, and hypertonic are used to relate the osmalirity of a cell to that of the extracellular fluid that contains the cell)

Cell Walls

Maintain water balance

Role of Osmosis in a cell

To balance the concentration of substances in the cell

Facillitation

Speeds molecule movement

Sodium-Potassium Pump

ex. of active transport system:

• pushes sodium out

• pulls potassium in

Membrane potential

The voltage difference across a membrane

Voltage

distribution of posiitive and negative ions across a membrane

Electrochemical graident

Drives the diffusion of ions

Electrogenic pump

transport protein that generates voltage across a membrane

Exocytosis

Transport vesicles migrate to the membrane, fuse with it, and release their contents

Endocytosis

Cell takes in macromolescules by forming vesicles from the plsma membrane

Phagocytosis

Cellular eating

Pinocytosis

Cellular drinking

Receptor mediated endocytosis

binding of ligands to receptors triggers vesicle formation