MCAT Biology

“The night is always darkest just before the dawn, but I assure you, the dawn is coming.”—The Dark Knight

Nuclear Membrane

maintains nuclear environment separate from the cytoplasm

Nuclear Pores

allow exchange between cytoplasm and nucleus

Nucleolus

rRNA is synthesized

Outer Membrane of Mitochondria

barrier between cytosol and inner environment

Inner Membrane of Mitochondria

arranged into cristae folds with molecules and enzymes of the electron transport chain

Mitochondria differ from other cells in that

they contains their own genes and replicate independently with binary fission, capable of killing the cell

Endosomes

transport, package, and sort material from the cell membrane

Rough ER

translation of proteins

Smooth ER

lipid synthesis and detox

Peroxisomes

break down fatty acid chains that beta oxidation

Microfilaments

made of actin, muscle contraction, cytokinesis cleavage furrow

Microtubules

hollow polymers of tubulin that build the pathways for motor proteins

9+2 structure

9 microtubules around 2 in the center; only in eukaryotic motility organelles

Four Tissue Types:

epithelial, connective, muscle, and nervous

Epithelial cells make

parenchyma, functional parts of the organ

Connective Tissue makes

stroma (bone, cartilage, blood)

Extracellular Matrix

made of connective tissue secretions

Both Archaea and eukaryotes

translation with methionine, similar RNA polymerase, DNA with histones

All bacteria contain

cell membrane and cytoplasm