Anatomy and Physiology 1 Chapter 3 and 4 Cellular Level

cells are

the building blocks of all plants and animals

all cells come from

division of pre-existing cells

cells are the smallest

units that perform all vital physiological functions

each cell maintains

homeostasis

somatic cells

all body cells except sex cells

sex cells(germ cells)

reproductive cells, male sperm, female oocytes(eggs)

plasma membrane

separates inside of cell from extracellular fluid

extracellular fluid

all body fluids outside of the cell

interstitial fluid

watery medium of tissues outside of the cell

function of cell membrane (4)

physical barrier

regulate exchange with the environment(ions and nutrients enter, waste and cellular products released)

sensitivity to environment (extracellular fluid, composition, chemical cells)

structural support (anchors cells and tissues)

membrane lipids/phospholipid bilayer

double layer of phospholipid molecules forms barrier to ions and water-soluble compounds

hydrophilic heads

toward water environment, both sides

hydrophobic fatty-acid tails

inside membrane

anchoring proteins(stabilizers)

attach to inside or outside structures

recognition proteins(identifiers)

label cells normal or abnormal

enzymes (membrane protein)

catalyze reactions

receptor proteins

binds and responds

carrier proteins

transport specific solutes through membranes

channels (membrane protein)

regulate water flow and solutes through membrane

functions of membrane carbs

specificity in binding(receptors)

recognition(immune response)

permeability

determines what moves in and out of the cell

freely permeable

lets anything pass

selectively permeable

restricts movement

impermeable

lets nothing in or out

active transport

requires ATP because moving substrates AGAINST gradient(move ions and uses ion pumps)

passive transport

no energy required

diffusion

movement of materials(molecules) from a high concentration to a low concentration

simple diffusion(passive)

materials diffuse straight through cell membrane

examples of simple diffusion

lipid soluble(alcohol, fatty acids, steroids)

dissolved gases(oxygen and carbon dioxide)

channel mediated diffusion

materials pass through channels

examples of channel mediated diffusion

ions, water soluble compounds

what passage depends on in channel mediated

size, charge, interaction with channel

osmosis

diffusion of water across cell membrane

hypotonic solutions

has less solutes, loses water through osmosis

MOLECULE WILL SWELL

hypertonic solutions

has more solutes, gains water through osmosis

MOLECULES WILL DEPLETE

isotonic solutions

a solution that does not cause osmotic flow of water in or out of cell

carrier mediated transport

proteins in the cell membrane carry material across

what does carrier mediated transport require

specificity, saturation limits(rate depends on proteins), regulation(cofactors, hormones)

examples of facilitated diffusion

passive and carrier mediated

facilitated diffusion

carrier proteins transport molecules too LARGE to fit through channel proteins

transport vesicles

small membranous sacs that move materials in and out

endocytosis

into the cell

receptor-meditated endocytosis

receptors(glycoproteins) bind target molecules, coated vesicle carries target molecules and receptors into the cell

pinocytosis

cell drinking, drink cellular fluid

phagocytosis

cell eating, engulfs LARGE objects

exocytosis

out of the cell and discharges contents outside of the cell

transport potential electrical charge

inside the cell membrane is slightly negative and outside is slightly positive

unequal charge across cell membrane is transmembrane potential

cytoplasm

all materials inside the cell and outside the nucleus

cytosol

the fluid, dissolved materials of nutrients, ions, proteins, and waste products

organelles

structures with specific functions

cytoskeleton (non-membranous)

structural proteins for shape and strength, provides internal protein framework, strengthen cell and anchor organelles

microvilli (non-membranous)

increase surface area for absorption, attach to cytoskeleton

cilia (non-membranous)

move fluids across cells surface, long extensions of cell membrane

centrioles (non-membranous)

form spindle apparatus during cell division

ribosomes (non-membranous)

protein synthesis

free ribosomes

in cytoplasm, proteins for cell

fixed ribosomes

in ER, proteins for secretion

proteasomes (non-membranous)

contains protein-digestive enzymes(proteases), disassembles damaged proteins for recycling

mitochondria (membranous)

produces energy for the cell, has smooth outer membrane and folded inner membrane

endoplasmic reticulum (membranous)

synthesis of proteins, carbs, and lipids

storage of synthesized molecules and materials

transport of materials within the ER

detoxification of drugs or toxins

rough ER(RER)

surface covered with ribosomes, active in protein and glycoprotein synthesis

smooth ER(SER)

no ribosomes attached, synthesize lipids and carbs

golgi apparatus (membranous)

(post office)

secretory vesicles: modify and package products for exocytosis

membrane renewal vesicles: add or removes membrane components

lysosomes: carry enzymes to cytosol

lysosomes (membranous)

powerful enzyme-containing vesicles, clean up inside cell

autolysis

self-destruction of damaged cells

peroxisomes

enzyme-containing vesicles, break down fatty acids, organic compounds produce hydrogen peroxide

nucleus

cell’s control center, largest organelle(its the home of the cell)

nuclear membrane

DOUBLE membrane around the nucleus(envelope)

nucleoli

synthesize(to make) RNA

nuclear Pores

small communication Passages

nucleosomes

DNA coiled around histones

chromatin

loosely coiled DNA(cells NOT dividing)

chromosomes

tightly coiled DNA(cells dividing)

DNA

instructions for every protein in the body

gene

are functional units of DNA, contain instructions for 1 or more proteins

nucleus contains chromosomes

chromosomes contain DNA

DNA stores genetic instructions for protein

proteins determine cell structure and function

nucleus summary

mitosis

division of a cell that produces 2 identical daughter cells

meiosis

cell division that produces gametes(sex cells with HALF number of chromosomes)

interphase

most of a cell’s life is spent in a nondividing state

prophase

chromosomes coil, centriole pairs move to cell poles, spindle fibers form between centriole pairs

metaphase

chromosomes align on the midline

anaphase

centriole’s microtubules pull chromosomes apart

telophase

nuclear membrane reforms, chromosomes uncoil, cell has 2 complete cells

cytokinesis

division(moving) of the cytoplasm

cell differentiation

differentiate/ specialize by turning off all genes not needed by the cell, specialized cells form tissues. it depends on which genes are active and inactive

oncogenes

mutated genes that cause cancer

tumor(neoplasm)

enlarged masses of cells, abnormal cell growth and division

benign tumor

contained, not life threatening

malignant tumor

spread into surrounding tissues(invasion), start new tumors(metastasis)

gene mutation

change in nucleotide sequence will change material