Ch 4 Cell Theory and Organelles Flashcards
what makes a cell a cell?
barrier, organelles, energy transfer, proteins, DNA
plasma membrane
fluid mixture of equal parts lipid and protein by weight. regulates movement of MOST substances in and out of cell, contains phospholipids, cholesterols, and glycoproteins
phospholipid bilayer
polar hydrophilic heads, nonpolar hydrophobic tails, ensures cytosol remains inside cell and interstitium outside
membrane cholesterol
support
membrane glycoproteins
maintain extracellular matrix
membrane proteins
half of plasma membrane by weight, float and move in fluid bilayer, perform most membrane functions
what are the six membrane proteins
transport, cell surface receptors, identify markers, enzymes, anchoring sites, cell adhesion
transport proteins
regulate movement of substances across membrane
cell surface receptors
bind molecules call ligands
identify markers
distinguish healthy cells from cells to be destroyed
enzymes
catabolize chemical reactions, could be internal or external
anchoring sites
secure cytoskeleton to plasma membrane
cell adhesion
perform cell to cell attachments
ligands
molecules that bind to macromolecules, ie a neurotransmitter released from a nerve cell that binds to the cell surface receptor of a muscle cell
a cell is only a cell if…
…plasma membrane is intact and functioning
cytoplasm
cellular components between plasma membrane and nucleus. includes cytosol, organelles, and inclusions
cytosol
viscous fluid of the cytoplasm, high water content, contains dissolved macromolecules and ions
organelles
complex organized structures within cells, unique shapes and functions
membrane bound
organelles enclosed by a membrane
non-membrane bound
composed of protein
nucleus
contains DNA instructions for building proteins, controls functions of cell
membrane bound
ribosomes
read genetic information coming from nucleus and translates it
non-membrane bound
rough endoplasmic reticulum
ribosomes attached, protein synthesis
membrane bound
smooth endoplasmic reticulum
lipid synthesis (liver) steroid synthesis (testes) absorption and transport of fats (intestines) detoxification (liver) molecule breakdown (liver)
membrane bound
golgi complex
logistics center: modifies proteins and lipids. vesicles move to membrane and contents expelled through exocytosis
membrane bound
lysosome
vesicles containing digestive enzymes - acidic (phagocytosis)
membrane bound
mitochondria
powerhouse of the cell. ATP production
membrane bound
cytoskeleton
made of fibrous proteins
microfilaments - actin
intermediate filaments - high tension strength; tendons, filaments
microtubules - function in intercellular matrix
non-membrane bound
centrioles
barrel shaped, base of cilia and flagella, important in mitosis
non-membrane bound