BIO 101 Ch. 1-5 Study Guide

Opioid receptors characterized as this protein group

transmembrane protein group

Amphipathic molecules

Molecule that contains hydrophobic and hydrophilic regions

Why phospholipid membranes form bilayers

Their polar heads are attracted to water and their nonpolar tails face away from water

The three opioid receptors

Mu, Delta, Kappa

Mu

The opioid receptor responsible for triggering brain reward system

Delta

The opioid receptor that plays a role in determining emotional state

Kappa

The opioid receptor associated with pain relief

Morphine acts on which opioid receptor?

Mu

Integral proteins

Proteins embedded within the phospholipid bilayer of the plasma membrane

Peripheral proteins

Proteins associated with the cytoplasmic side in the plasma membrane

Components of the plasma membrane as described by the fluid-mosaic model

phospholipids, cholesterol, proteins

An increase in the amount of unsaturated fatty acid residues causes bilayer fluidity to

increase

Hydrophilic heads of the plasma membrane’s phospholipid bilayer point towards

water on the outside and inside of membrane

Components of a glycolipid

phospholipid & carbohydrate

Components of a glycoprotein

protein & carbohydrate

Membrane proteins

Plasma membrane components that can function as channels, carriers, receptors, and enzymes

Channel proteins

Proteins that play a role in passing molecules through the membrane

Carrier proteins

Proteins that are involved in transporting selective molecules across the cell membrane

Cell recognition proteins

Proteins involved in the immune response

Enzymatic proteins

Proteins involved in catalysis of metabolic reactions

Receptor proteins

Proteins involved in sending signals to the cell/binding to specific molecules that brings about cellular response

Fluid-mosaic model

Interactions between the cell membrane

Junction proteins

Group of proteins that enable cells to work together to function as a tissue

Concentration gradient

Gradual change in chemical concentration between two areas of differing concentrations

Diffusion

Movement of molecules from a higher concentration to a lower concentration until equilibrium is achieved

Osmosis

Diffusion of water across a selectively permeable membrane from high to low concentration

Isotonic solution

Solution equal in solute concentration to that of the cytoplasm of a cell; causes cell to neither lose nor gain water through osmosis

Tonicity

Strength of the solution/solute concentration of a solution compared to that of a cell

Hypotonic solution

Solute that contains a lower-solute (more water) concentration than the cytoplasm of a cell; causes cell to gain water by osmosis

Cytolosis

Used to refer to cells that have been disrupted

Hemolysis

Rupturing or bursting of a red blood cell being placed in a hypotonic solution

Turgor pressure

Pressure of the cell contents against cell wall; in plant cells, determined by water content of vacuoles; provides internal support

Crenation

Shriveling of cell due to water leaving cell when environment is hypertonic (animal cells)

Plasmolysis

Concentration of the cytoplasm due to loss of water (plant cells)

Exocytosis

Process in which can intracellular vesicle fuses with the plasma membrane —> vesicles contents released outside cell

Endocytosis

Process by which substances are moved into the cell from the environment; includes phagocytosis, pinocytosis, receptor-mediated endocytosis

Phagocytosis

Type of endocytosis that transports large substances

Pinocytosis

Type of endocytosis that transports small substances

Receptor-mediated endocytosis

specialized form of pinocytosis

Hypertonic solutions

Cause cells to shrink because water leaves the cell

Active transport

Movement of molecules against their concentration gradient; a carrier protein uses ATP to combine with subject molecules, causing it to change shape and allowing it to move against the gradient

Bulk transport

Vesicles created by cell to transport molecules too large to be transported across the plasma membrane by a carrier protein

Often the source of vesicles used for exocytosis

Golgi body

Source of vesicles used for endocytosis

plasma membrane

Regulated secretion

Specific needs of body triggering vesicles to fuse with plasma membrane

Extracellular matrix

Nonliving substance secreted by some animal cells; composed of a protein and polysaccharides

Intergens

Integral membrane proteins that connect to fibronectin externally and to actin cytoskeleton internally; plays a role in cell signaling, permitting the extracellular matrix to influence activities of cytoskeleton and share activities of cell

Proteoglycans

Assist cell signaling when they regulate passage of molecules through extracellular matrix to plasma membrane

Adhesion junction

Mechanically attach adjacent cells

Demosomes

Internal cytoplasmic plaques firmly attach to the intermediate filament cytoskeleton within each cell and are joined between cells by integral membrane proteins called cadherins

Cadherins

Join desmosomes between cells

Tight junctions

Connect plasma membranes between adjacent cells together, producing zipper-like fastening

Gap junction

Formed when two identical plasma membrane channels join

Plasmodesmata

Cytoplasmic connections in the cell wall that connect two adjacent cells (plants)

Collagen

Provides resistance to stretching in extracellular matrix

Collagen and elastin

Structural proteins in the extracellular matrix

Lignin

Found in secondary cell walls of plant cells and adds strength to them

Phospholipid bilayer

External surface lined with hydrophilic polar heads; Cytoplasmic surface lined with hydrophilic polar heads; Nonpolar, hydrophobic, fatty-acid tails sandwiched in between

Cholesterol

Affects the fluidity of plasma membrane

Glycoprotiens

Proteins with attached carbohydrate chains

Glycolipids

Lipids with attached carbohydrate chains

Molecules that pass freely through the plasma membrane by passing through phospholipid bilayer

Small, non-polar molecules

Aquaporins

Specialized proteins that speed up water transport

Osmotic pressure

Pressure that develops due to osmosis

Rough Endoplasmic Reticulum

Studded with ribosomes & synthesizes proteins

Nucleus

Contains DNA

Lysosomes

Contains enzymes that digest worn-out organelles

Mitochondria

Synthesizes ATP

Cytoskeleton

Network of protein structures that extend throughout the cytoplasm

Smooth Endoplasmic Reticulum

Synthesizes lipids; detoxifies drugs, etc.

Chloroplasts

Site of photosynthesis

Peroxisomes

Synthesizes lipids; detoxifies drugs, etc.

The component of the cytoskeleton not considered a macromolecular fiber

Centrosome

Actin filaments

Maintains cell shape and support for microvilli in intestinal cells; intracellular traffic control

Golgi apparatus

Modifies proteins and lipids

Ribosomes

Site of protein synthesis; composed of RNA

Flagella

Provides motility

Fimbriae

Small, bristle-like fibers that sprout from the cell surface

Conjugation pili

Rigid, tubular structures used to pass DNA from cell to cell

Functional Groups

A cluster of specific atoms bonded to a carbon skeleton is known as:

DNA

Stores genetic information

RNA

Transports genetic info; regulates gene expression

Adenine

Pairs with thymine in double-strand; pairs with uracil in single strand

Guanine

Pairs with cytosine in double-strand; pairs with cytosine in single-strand

RNA bases

Adenine, uracil, cytosine, guanine

DNA bases

Adenine, guanine, thymine, cytosine

Three parts of a nucleotide

Phosphate, pentose sugar, nitrogenous base

Primary protein structure

Linear sequence of amino acids

Secondary protein structure

Characterized by presence of alpha helices and beta sheets held in place with hydrogen bonds

Tertiary protein structure

Overall three-dimensional shape of a polypeptide; stabilized by presence of hydrophobic interactions, hydrogen, ionic, and covalent bonding

Quaternary protein structure

Consists of more than one polypeptide

Chaperone proteins

Help proteins fold into their normal shapes and may also correct misfolding of new proteins

Polypeptides

Long chains of amino acids joined together

Peptides

Two or more amino acids joined together

Phospholipid membrane components

One glycerol molecule linked to two fatty acids and a modified phosphate group

Unsaturated fatty acid

One or more double bonds between carbons; tend to be liquid at room temperature

Saturated fatty acid

No double bonds between carbons; tend to be solid at room temperature

Transfats

A triglyceride with at least one bond in a trans formation

Lipids

Large, non polar molecules that are insoluble in water; long-term energy storage

Examples of lipids

Fats, oils, phospholipids, steroids, waxes