Chapter 6.3 and 6.4-Major components of Eukaryotic cells

Major components of Eukaryotic cells

DNA is stored

nucleus

RNA

Converted from DNA in the nucleus

Nuclear Pore

How RNA Leaves the nucleus

Ribosomes

uses the info from DNA (through the RNA) to create proteins

Chromosomes

DNAs discrete unit, formed when the cell is about to divide

DNA and Choromosomes proteins

chromatins

Nucleolus

is inside the nucleus and is the site of ribosomal RNA (rRNA) synthesis

Ribosomes

particles made of rRNA and carry out protein synthesis

Ribosomes carry out protein sythesis is two locations

1- cytosol (free)

2- one the outside of the endoplasmic recticulum or the nuclear envelope (bound)

Proteins made by free ribosomes

remain within the cells

Proteins made by bound ribosomes

are secreted from the cells or inserted into the membrane

Parts of the Endomembrane system

• plasma membrane

• nuclear envelope

• endoplasmic recticulum

• golgi apparatus

• lysosomes

• vacuoles

All components of the Endomembrane system

share a continuous membrane with one another

Vesicles

transfer portions of membrane between different endomembrane components

Endoplasmic reticulum

more than half the total membrane in eukaryotic cells, continuous with the outer membrane of the nuclear envelope

smooth ER

lacks ribosomes

Rough ER

surface is studded with ribosomes

Tubules and flattened sacs in a membranous system, cisternae

golgi apparatus

ER Lumen

cisternal space, enclosed by the ER membrane

Smooth ER functions

• synthesizes lipids

• metabolizes carbohydrates

• detoxifies drugs and poisons (Liver)

• stores calcium ions (Muscles)

Rough ER

• synthesizes proteins

• distributes transport vesicles

• membrane factory

as a polypeptide grows from a bound ribosome

the chain is threaded into the ER lumen through a pore in ER membrane

Transport vesicles

membranes enclosing proteins that bud from the ER and are delivered to the Golgi apparatus

functions of the golgi apparatus

• modifies products produced by the ER

• produces and modifies certain macromolecules (polysaccharides)

• sort and packages molecules (proteins, ploysaccharides and lipids) into transport vesicles or insertion into other cellular membranes

lysosome

membranous sac of hydrolyic enzymes that and animal cell can use to digest macromolecules

lysosomal enzymes can

hydrolyze protiens, fats, polysaccharides, and nucleic acids

Lysosomal enzymes work best

in acidic environments in the lysosomes, which protects the rest of the cell from the enzymes

Macrophages

can engulf other cells like bacteria

Phagocytosis

this forms a food vacuole inside the specialized cell, lysosome fuses with the food vacuole and digests the bacteria

Autophagy

lysosomes use enzymes to recycle the cells own organelles and macromolecules

Vacuoles

fungi or plant cells have one or more derived from the endoplasmic recticulum and golgi apparatus.

food vacuoles

formed by phagocytosis

contractile vacuoles

found in freshwater protists, pump excess water out of cells

central vacuoles

found in many mature plant cells, hold organic compounds and water

the largest component in a plant cell

central vacuoles

Endomembrane system

communicates with vesicles

anything that effects one member of the endomembrane system …

affects the others