MaryBiraiCells
Endocytosis
Exocytosis: Sending something out. Ex: goblet cells.
Cytoplasm
Receptor mediated endocytosis: requires proteins. Selective.
Phagocytosis: Doesn't make a vescicle. Cell expands to engulf a whole cell. Phago means eating.
Pinocytosis: means drinking. vescicle is formed in plasma membrane. Non selective.
Nucleus: Control Center
Organelles: small part of the cell that performs a certain function
Cytosol: liquid portion of the cell not including the organelles
Plasma Membrane
Only allows some things to pass through
Membrane Transport
Phospholipid bilayer & proteins. Proteins have receptors that transmit info from outside to inside the cell.
Golgi Apparatus: a stack of smooth membrane sacs close to the E.R. Function:Exports from cell, enlarges plasma membrane, and lysosome formation
Lysosomes: Membranous sacs containing enzymes. Function: sites of intracellular digestion
Smooth ER: membranous system of sacs and tubules; free of ribosomes. Function: site of lipid and steroid hormone synthesis, lipid metabolism, and drug detox
Microtubules: cylindrical structures made of tubulin. Function :support the cell and give it shape. Form centrioles
Rough Endoplasmic Reticulum (ER): Membrane system of sacs and tubules externally studded with ribosomes. Function: makes proteins that are secreted from the cell; makes cell membrane
Peroxisomes: membranous sacs of oxidase enzymes. Breaks down toxic substances (many of them in liver)
Microfilaments: Fine filaments of the contractile protein actin. Involved in muscle contraction. Helps form cells cytoskeleton. Can produce cytoskeleton
Outside of Nucleus
Most cellular activities occur here
Inside plasma membrane
Simple Diffusion
Facilitated Diffusion
Active Transport
Simple because it requires no cellular energy
If simple diffusion is about water its osmosis
Movement of something down a concentration gradient until equilibrium is reached
Requires no cellular energy
Requires protein
Movement down a concentration gradient until equilibrium is reached
Large molecules like glucose
Not soluble in lipids
Requires cellular energy
Movement against a concentration gradient
Requires a protein
there is more of the substance outside the cell than inside
Charged particles
Ribosomes: small dense particles consisting of two subunits, each composed of ribosomal RNA and protein. FREE or ATTACHED to rough Endoplasmic Reticulum (ER). Function is protein synthesis
Mitochondria: rodlike, double membrane structure. Function: site of ATP synthesis; powerhouse of the cell.
Intermediate Filaments: protein fibers. Function: Stable (permanent) cytoskeletal elements. Resist tension forces acting on cell.
Centrioles: paired cylindrical bodies. Function: involved in the process of mitosis-separation of chromosomes
Surrounded by the nuclear envelope. Contains fluid nucleoplasm, nucleolus, and chromatin
Function: responsible for transmitting genetic information and providing the instructions for protein synthesis
This is where we find DNA.
Components of Nucleus
Nucleolus: dense spherical bodies; Function: Site of ribosome subunit manufacture
Chromatin: granular, threadlike material composed of DNA and histone proteins. Function: DNA constitutes the genes.
Nuclear envelope: a double membrane structure that's continuous with the cytoplasmic ER. Function: separates the nucleoplasm from the cytoplasm and regulates passage of substances to and from the nucleus.
Cytosol + Organelles