Anatomy & Physiology: Exam Chapter 3

Cell metabolism / energy use

Synthesis of molecules

Communication

Reproduction

Inheritance

Boundary - separates intracellular/extracellular

Determines what moves into/out of cells

The charge difference across the plasma membrane. Outside is more positively charged than inside due to gathering of ions on plasma membrane.

A double layer of phospholipid molecules. Have polar (hydrophilic) head and nonpolar (hydrophobic) tail.

A collection of glycolipids (carb + lipid), glycoproteins (carb + protein) and carbohydrates on the outer surface of the PM (plasma membrane).

Water loving. Heads of lipids are positively charged and exposed to extracellular and intracellular fluids of cell.

Water fearing. Tails face the interior of the plasma membrane.

Interspersed among phospholipids and accounts for 1/3 total lipids in plasma membrane.

Distribution of molecules in the membrane.
Phospholipids can automatically reassemble with damage.
Membranes can fuse.

Integral (intrinsic) - penetrates deeply into lipid bilayer

Peripheral (extrinsic) - attached to either inner/outer surfaces of lipid bilayer

Marker molecules

Attachment proteins

Transport proteins

Receptor proteins

Enzymes

Located on cell surface.

Allows cells to identify other molecules/cells. Usually glycoproteins or glycolipids

Allow cells to attach to each other or to extracellular molecules.

Cadherins: cells to other cells
Integrins: cellular membrane proteins to extracellular molecules

Non-gated: always open

Ligand-gated: open/closed in response to chemical signals
Voltage-gated: open/close in response to change in charge across plasma membrane

Transporters.
Move molecules from one side of plasma membrane to the other by changing shape.

Uniporters - moves one particle
Symporters - 2 particles in same direction
Antiporters - 2 particles in opposite direction

Diffusion
Osmosis
Mediated transport
Active transport

Diffusion - movement of solutes from high concentration to low concentration.

Osmosis - diffusion of solvent (water) across a selectively permeable membrane (allows water but not all solutes in water).

The force required to prevent water from moving across a SP membrane.

Isosmotic - same concentration of solutes/same pressure

Hyperosmotic - greater concentration of solute particles, higher osmotic pressure.

Hypoosmotic - lesser concentration of solute particles, lower osmotic pressure (more dilute solution)

Isotonic - cell placed in solution, neither shirnks nor swells

Hypertonic - cell placed in, water moves OUT, cell shrinks (crenation)

Hypotonic - cell placed in, water moves INTO cell and cell bursts (lysis)

IMPORTANT FOR FLUID ADMINISTRATION IN DEHYDRATED PATIENTS.

Process by which transport proteins mediate or assist, movement of large water soluble molecules or electrically charged molecules/ions across plasma membrane.

Specificity - each transport protein binds to/transports only one ion/molecule

Competition - result of similar molecules binding to transport protein

Saturation - rate of movement of molecules across membrane is limited by number of available transport proteins

Passive transport - cell does not expend metabolic energy. (diffusion, osmosis, facilitated diffusion)

Active transport - cell expends metabolic energy. (can move substances from low to high with ATP and high to low)

A carrier-mediated or channel-mediated passive membrane transport process that moves substances into or out of cells from high to low. Does not require ATP.

Active transport of an ion out of a cell from low to high concentration. The tendency for the inos to move back provides energy necessary to move a different ion or other molecule into the cell.

Moves by symport or antiport.

Sodium/Potassium or glucose movement.

Endocytosis - uptake of material into cell by formation of a vesicle. PM wraps around particle/droplet and fuses so the membrane "eats" the particle/droplet.

Exocytosis - secretions that accumulate within vesicles cause these vesicles to fuse to the PM and the vesicle contents are expelled from cell.

Cellular material outside the nucleus but inside plasma membrane. Composed of cytosol, cytoskeleton, cytoplasmic inclusions and organelles.

Fluid portion of cytoplasm. Contains cytoskeleton/cytoplasmic inclusions.

Supports the cell and holds nucleus and other organelles in place.

Responsible for allowing movement of cell organelles and changes in cell shape.

Microtubules - internal scaffolding, assist with transport/cell division

Actin filaments - offers support, supports microvilli, helps with contractibility/movement

Intermediate filaments - offer mechanical strength to cells

Aggregates of chemicals either produced or taken in by cell. Includes chemicals for energy storage, pigmentation or for transporting other molecules.

Large, membrane-bound structure near center of cell. Houses majority of DNA - organized into structures called chromosomes.

Nucleoplasm - cytoplasm of nucleus
Nuclear envelope - PM of nucleus
Nucleolus - nucleus of nucleus

Fibrous structures of DNA and protein called chromatin.

Chromatids joined together by centromere and become a chromosome.

Site of protein synthesis.

FREE or ATTACHED (to ER)

(makes packages)

Consists of broad, flat interconnected sacs/tubules - cisternae - separate from rest of cytoplasm.

Rough ER - ribosomes attached; protein production
Smooth ER - no ribosomes; lipid production

(ships packages)

Packaging/distribution center for proteins/lipids manufactured by ER.

Create lysosomes - membrane bound vesicles that may include hydrolytic enzymes that function as digestive enzymes.

POWERHOUSE!

Provides energy for cell with ATP synthesis.

Inner foldings - cristae…make up the matrix.
Mitochondria increase in # when cell energy requirements increase.

Located close to nucleus in centrosome - specialized zone for microtubule formation.

Centrioles - move to poles before cell division and organize spindle cell fibers.

Spindle cell fibers - bind to chromosomes to facilitate movement of chromosomes toward two centromeres.

Structures that project from the surface of cells and are capable of movement.

1-1000's per cell.

Longer cilia - sperm cells are only human cells that possess flagella. One per cell.

Extension of plasma membrane that increases surface area. Not used for movement. Much smaller than cilia.

Functional units of hereditary (transmission of traits from parents to offspring)

Production of proteins from information stored in DNA.

All nucleated cells (except germ cells) have full complement of DNA. During development, differentiation occurs and some segments are turned off.

"copying the recipe"

Synthesis of types of RNA based on DNA sequence. One DNA strand serves as template for transcription.

"making the cake"

Synthesis of a protein at the ribosome in response to codons of mRNA.

The sequence of bases on a DNA strand.

Bases (letters)
Codons (three letter words)
Protein (words into sentences)
Chromosomes (sentences into book)
Genome (books of library)

Interphase - 90% of time

| Mitosis - 10% of time

G1 (1st gap phase) - cell carries out routine metabolic activities
S (synthesis phase) - new DNA synthesized
G2 (2nd gap phase) - cell prepares for division

Prophase: chromatin condenses and forms mitotic chromosomes
Metaphase: chromosomes align near center
Anaphase: chromatids separate
Telophase: nuclear envelope forms, two separate nuclei

Occurs after mitosis - separation of cytoplasm between two new cells.

A type of cell division specialized for sexual reproduction.

One cell undergoes two divisions to produce four genetically different daughter cells. One homolog from each homologous pair.

Diploid (2 chromosomes: 2n) - first division - 2 cells
Haploid (1 chromosome: 1 n) - second division - 4 cells - EGG/SPERM

Genetic disorder is an abnormality in DNA. A birth defect is due to developmental problems.

Teratogens (radiation, drugs, alcohol, etc.)

| Do not cause abnormalities in DNA.

Mutagenes - agents that cause mutations

| Oncogenes - DNA replication on steroids (some genetic and some from exposure to carcinogens)

Anything that increases the risk of cancer.