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