Cells and Cell Functions

Cells

Cells

smallest units that perform vital physical functions

Cell membrane

outer boundary of the cell, aka. plasma membrane or plasmalemma

• isolation, regulates exchanges, structural support

• phospholipids, proteins(integral proteins or channel proteins), carbs

Cytoplasm

substance that holds organelles, has more proteins than extracellular fluid,

Nucleus

control center of cell, nuclear membrane, nucleoli

Passive transport

high concentration to low

• simple diffusion, osmosis, filtration

Osmosis

force of water movement, towards a concentration of higher solute

• isotonic(equal), hypotonic(flow into), hypertonic(flow out of)

Active transport

substances from low concentration to high concentration

• endocytosis(pino/phagocytosis), exocytosis, sodium-potassium exchange pump

Non-membranous organelles

cytoskeleton, microvilli, centrioles, flagella, cillia, ribosomes

Membranous organelles

mitochondria, endoplasmic reticulum, golgi apparatus, lysosomes, perioxisomes, nucleus

Ribosomes

protein synthesis

Endoplasmic reticulum

interconnected membrane with nuclear membrane

• synthesis, storage, transport, detox

Smooth ER

synthesis and detox, storage and removal of calcium

Rough ER

protein synthesis (ribosomes), and protein storage

Golgi apparatus

communicates with vesicles to ER and cell surface

• synthesis and packaging of secretions, renewal and mod of cell surface, packaging of enzymes

Lysosomes

from golgi, contain enzymes to digest, defend against diseases, and recycle; "trash compacter and recycler"

mitochondria

powerhouse, double membrane

Cytoskeleton

a microscopic network of actin filaments and microtubules in the cytoplasm of many living cells that gives the cell shape and coherence

Microvilli

finger-like extensions, located in lining of digestive tract

Cilia

hair-like extensions, lining respiratory tract and fallopian tube

flagella

tail-like projections, sperm cells

Nuclear membrane

contains nuclear pores, selectively permeable

nucleolus

of rna and proteins, synthesizes ribosomes and ribosomal DNA

Chromosomes

twisted DNA strands into a double helix

DNA replication

dna uncoils, hydrogen bases break, serves new template, line up with compliments, polymerase links back up

Protein synthesis

transcription: copies info from a segment of DNA into mRNA

• mRNA leaves to ribosome with compliment of DNA translation: translates the codons of the mRNA with tRNA into protein

Cell division

IPMAT interphase, prophase, metaphase, anaphase, telophase, (cytokinesis)

interphase

normal cellular functions, prep for division, cell growth and dna replication

prophase

pairs of chromosomes are made apparent as nuclear membrane falls, centrioles form at the poles to form spindle fibers

metaphase

chromosomes line in the middle (metaphase plate), centromeres attach to spindle fibers

anaphase

centromeres separate pulling chromosomes to the poles, cytokinesis begins

telophase

chromosome migration complete, nuclear membrane forms around chromosomes, cleavage furrow apparent

cytokinesis

true division of the cell