Cell Parts and Central Dogma

lipids, carbohydrates, nucleic acids, proteins

4 major classes of cell biomolecules

central dogma

DNA transcription, RNA translation, protein

codons

nucleotide triplets that encode amino acids

degenerate

1 amino acid can be coded by more than 1 codon

chromosomes

DNA molecules, humans have 23 pairs

genes

linear stretches of DNA on the chromosome that encode proteins

genome

all chromosomes together

organelles

membrane-bound structures in cell

plasma membrane

hydrophobic phospholipid bilayer that regulates what goes in and out of the cell, fluid mosaic with embedded proteins

typical mammalian cell size

10 micrometers

nucleus

separates DNA from cytoplasm, separates RNA transcription from protein translation, takes up ½ of cell

cytoplasm

cytosol and all organelles except nucleus

nucleolus

where ribosomes are synthesized

nuclear envelope

membrane that surrounds nucleus made of 2 lipid bilayers

nuclear pores

where soluble materials diffuse in and out

smooth endoplasmic reticulum

network of closed membrane tubules and vesicles responsible for lipid synthesis, calcium ion storage for cell signaling, detoxification, 100 micrometers

lumen

aqueous solution inside an organelle

rough endoplasmic reticulum

flattened sacks studded with ribosomes that synthesize membrane and extracellular proteins, 100 micrometers

ribosomes

not organelles (not membrane-enclosed), protein and RNA subunits that use mRNA to synthesize protein

gogli complex

flatted compartments and vesicles where proteins and ER products are processed and modified by enzymes, 100 micrometers

lysosomes

acidic lumen degrades material from extracellular environment, 100 micrometers

acid hydrolase

enzyme carrying out degradation reaction in lysosome

mitochondria

folded cristae with matrix filling, has its own chromosomes and ribosomes, site of ATP production via aerobic metabolism, few micrometers

cytoskeleton

long fibron proteins that give cell structure