General Biology 1 - Exam 2 Review

Prokaryotes

[] are included in the domains bacteria and archea

Eukayotes

[] are included in the doman Eukarya

Domain Eukarya

Includes Plants, Fungi, and Animals

Cell

The fundamental unit of life

Prokaryotic Cells

No nucleus, No true organelles

Eukaryotic Cells

Nucleus, Has Organelles

Magnification

The ratio of an object's image size to its real size

Resolution

The measure of the clarity of the image, or the minimum distance of two distinguishable points

Contrast

Visible differences in parts of the sample

Flourescence Microscope

Microscope that uses florescence instead of reflection and absorption

Fluorophore

A functional group in a molecule which will absorb energy of a specific wavelength and re-emit energy at a different wavelength

Confocal Microscope

Microscope that provides sharper images of 3D tissues and cells

Scanning Electron Microscope

A microscope that focus a beam of electrons onto the surface of a specimen

Transmission Electron Microscope

A microscope that focus a beam of electrons through a specimen

Volume of a Cell

[] determines the amount of chemical activity in the cell

Surface Area of a Cell

[] determines the amount of substances that can pass the cell boundary

Cytoplasm

Semifluid substance enclosed by the cell's plasma membrane where most cellular activities occur

Cytosol

Portion of a cell that is not enclosed within membrane-bound organelles and is also part of the cytoplasm

Cytoplasmic Inclusions

Insoluable suspended substances found in cytosol that include stored nutrients and secretory products

Nucleus

Contains the cell's genetic material

Nuclear Envelope

A double membrane that constitutes the outer boundary of the nucleus

Nucleoplasm

A highly viscous liquid that surrounds the chromosomes and nucleolus inside the nucleus

Nuclear Lamina

Dense fibrillar network composed of intermediate filaments and membrane associated proteins that provides mechanical support, regulates important cellular events such as DNA replication and cell division

Nucleolus

A non-membrane bound structure composed of proteins and DNA found within the nucleus

Ribosomes

Site of protein synthesis, can be bound to the endoplasmic reticulum or floating in the cytoplasm

Endomembrane System

Regulates protein traffic and performs metabolic functions in the cell (Makes and modifies proteins, recycles molecules)

Rough Endoplasmic Reticulum

Allows ribosomes to synthesize proteins

Smooth Endoplasmic Reticulum

Produces lipid compounds such as phospholipids, steroids, and fatty acids

Vesicles

A small membrane-enclosed sac that can store or transport substances or digest cellular products and waste

Vacuoles

Contains water and food in plants

Lysosomes

An organelle that contains digestive enzymes used to break down substances in the cell into smaller compounds

Transport Vesicles

A type of vesicle that can move molecules between locations inside the cell

Secretory Vesicles

A type of vesicle that contains materials that are to be excreted from the cell

Peroxisomes

Detoxifies harmful substances like free radicals

Golgi Apparatus

A system of membranes that modifies products of the ER and sorts and packages materials into transport vesicles

Mitochondria

An organelle that produces ATP and is involved in signaling, cellular differentiation, cell death, and control of the cell cycle

Outer Membrane of the Mitochondria

Contains proteins for transport called porins

Intermembrane Space of the Mitochondria

Space between the inner and outer membrane

Inner Membrane of the Mitochondria

Area where the electron transport chain takes place

Cristae of the Mitochondria

Expands the surface of the inner membrane which enhances its ability to produce ATP

Matrix of the Mitochondria

Space enclosed by the inner membrane that is important in the production of ATP

Cytoskeleton

A network of fibers extending throughout the cytoplasm and it organizes the cell's structures and activities and it anchors many organelles

Microtubules

A hollow rod composed of tubulin proteins that makes up part of the cytoskeleton in all eukaryotic cells and is found in cilia and flagella, involved in movement

Microfilaments

A cable composed of actin proteins in the cytoplasm of almost every eukaryotic cell, making up part of the cytoskeleton and acting alone or with myosin to cause cell contraction; also known as an actin filament.

Intermediate Filaments

A component of the cytoskeleton that includes filaments intermediate in size between microtubules and microfilaments. They lock cells and tissues together, stabilize cell structure, and support cell shape.

Motor Protein

A protein that interacts with cytoskeletal elements (microfilaments and microtubules) and other cell components, producing movement of the whole cell or parts of the cell.

Centrosome

A structure present in the cytoplasm of animal cells that functions as a microtubule-organizing center and is important during cell division. A centrosome has two centrioles.

Centriole

A structure in the cenrosome of an animal cell composed of a cylinder of microtubule triplets arranged in a 9+0 pattern.

Cilia

Short, hairlike structures that project from the plasma membrane of some eukaryotic cells which propels the cell

Flagella

Whiplike structures that propel cells such as sperm through fluid

Plasma Membrane

A cell's outermost membrane that surrounds the cell and controls which substances move in and out

Lipid Bilayer

Structural foundation of cell membranes - phospholipids arranged tail-to-tail in a bilayer

Phospholipids in the Plasma Membrane

Polar head and nonpolar tail

Cholesterol in the Plasma Membrane

Makes membrane a bit more rigid

Proteins in the Plasma Membrane

Provide means of transport through membrane

Carbohydrates in the Plasma Membrane

Recognition patterns for cells and organisms; attached to the lipids or proteins

Fluidity of Membranes

Phospholipids in the plasma membrane can move within the bilayer; Most of the lipids, and some proteins, drift laterally; Rarely does a molecule flip-flop transversely across the membrane

The Fluid Mosaic Model

A mosaic of proteins and lipids that functions as a selectively permeable barrier that seperates an internal environment from an external one

Selective Permeability

Membrane property that allows some substances, but not others, to cross

Nonpolar Molecules through Bilayer

These can dissolve in the lipid bilayer and pass through the membrane rapidly

Polar Molecules through Bilayer

These molecules do not cross the membrane easily (Ex: Sugars)

Transport Proteins

These proteins allow passage of hydrophilic substances across the membrane; each type of these proteins moves a specific ion or molecule across a membrane

Aquaporins

These channel proteins facilitate the passage of water

Channel Proteins

A type of transport protein that have a hydrophilic channel that certain molecules or ions can use as a tunnel

Peripheral Membrane Proteins

These membrane proteins lack exposed hydrophobic groups and do not penetrate the bilayer

Integral Membrane Proteins

These membrane proteins have hydrophobic and hydrophilic regions or domains

Transmembrane Proteins

These membrane proteins are integral proteins that extend all the way through the phospholipid bilayer

Receptor Proteins

Proteins that are required for transmission of information to and from a cell; they respond to different extracellular stimulating molecules

Receptor Sites

These interact specifically with signal molecules

Glycoproteins

A surface level protein that have the carbohydrate portion projecting out of the cell and into the extracellular space; these give the cell a biochemical personality

Passive Transport

Concentration gradient drives a solute across a cell membrane through a transport protein; requires no energy input

Active Transport

A transport protein use energy to pump a solute across a cell membrane against its concentration gradient; moves substances from an area of lower concentration to an area of higher concentration

Diffusion

Net movement of molecules or ions from a region of higher concentration to a region of lower concentration

Facilitated Diffusion

A process of passive transport, facilitated by integral proteins

Primary Active Transport

A type of active transport that requires direct hydrolysis of ATP to drive the movement of substances against their concentration gradient

Secondary Active Transport

A type of active transport where energy comes from an ion concentration gradient that is established by primary active transport

Uniporter

A protein that transports one substance in one direction

Symporter

A protein that transports two different substances in the same direction

Antiporter

A protein that transports two different substances in opposite directions

Concentration

Measure of how much of a given substance there is mixed with another substance; # of molecules/ions per unit volume of a fluid

Concentration Gradient

Difference in concentration of a substance between adjoining regions of a fluid

Simple Diffusion

The process of random movement toward equilibrium

Osmosis

Net diffusion of water molecules across a selectively permeable membrane between two fluids with different water concentrations down a water potential gradient

Tonicity

The ability of a surrounding solution to cause a cell to gain or lose water

Isotonic Solution

A solution where the solute concentration is the same as that inside the cell; no net water movement across the plasma membrane

Hypertonic Solution

A solution where the solute concentration is greater than that inside the cell; cell loses water

Hypotonic Solution

A solution where the solute concentration is less than that inside the cell; cell gains water

Bulk Transportation

large numbers of molecules can be exchanged with extracellular fluid simultaneously; requires energy; vesicles are used

Endocytosis

Process by which a cell takes in a small amount of extracellular fluid (and its contents) by the ballooning inward of the plasma membrane; vesicles are formed during this process

Exocytosis

Process by which a cell expels a vesicle's contents to extracellular fluid by merging the vesicle with the plasma membrane

Phagocytosis

A type of endocytosis in which a cell engulfs particles in a vacuole and fuses the vacuole with a lysosome to digest the particle

Autocrine

A chemical signal that affect the cell that made them

Paracrine

A chemical signal that affect nearby cells

Direct Cell-Cell Contact

The signal and the receptor are both surface molecules

Endocrine Signaling

The secreted signals enter the circulatory system and the signals can reach distant target cells

Paracrine Signaling

The secreted signals reach neighboring cells by diffusion and the signals do not enter the circulatory system

Autocrine Signaling

The secreted signal can trigger a response in the same cell

Synaptic Signaling

A special type of paracrine signaling where the target cell is the postsynaptic cell and the signals are neurotransmitters that come from a neuron and reach the target cell through the synapse

Receptor

Only the cell with the specific [] to that specific chemical signal can receive the signal and elicit a response

Ligand

A molecule that binds specifically to another molecule, usually a larger one.