eukaryotic cells

to know:

Cell organelles and function:

Ribosomes: protein factories

• not considered an organelle

• complex made out of rna and protein

• carry out protein synthesis

Builds proteins in 2 locations

• in the cytosol (free ribosome)

• on the outside of the endoplasmic reticulum or the nuclear envelope

ER

• synthesis of proteins

• transport of proteins into membrane and organelles

• metabolism and movement of lipids

• detoxification

• these components are either continuous or connected via transfer by vesicles

• Smooth ER: synthesis of lipids

Endoplasmic reticulum

• accounts for more than half of the total membrane in many eukaryotic cells

• network o membrane

• ER membrane- continuous with nuclear envelope

• consist of tubular membrane and flattened sacs called eisternae

• 2 distinct regions of er: smooth and rough

• smooth: lacks ribosomes

• rough: surface is studded with rib

Endomembrane system

• regulates protein traffic and metabolic functions

• consist of:

  • nuclear envelope

  • endoplasmic reticulum

  • golgi apparatus

  • lysosomes

  • vacuoles

  • plasma membrane

Nucleus

• contains most of the cells genes also most visible

• the nuclear envelope encloses the nucleus separating it from the cytoplasm

• pore complex: regulates the entry and exit of the rna, proteins and makromolecules

• nuclear lamina: composed of proteins that maintains the shape of the nucleus

• dna is organized into chromosomes, each contains one dna molecule associated with histones

• chromatines- complex of dna and proteins

• nucleolus- site of rRna

• synthesis- ribosomal rna

Eukaryotic cells

• single or multicellular organisms

• DNA in a nucleus that is bounded by a double membrane

• membrane. bound organelles

  • provide different environments that supports specific metabolic functions

  • generally much larger than prokaryotic cells

  • plant and animal cells have most of the same organelles