Cell Anatomy & Organelles

Nucleus:

• Contains most of the genetic info in the eukaryotic cell (some genes are located in mitochondria and chloroplasts)
• Contains 1 or more nucleolus
• surrounded by nuclear envelope

Nuclear envelope: a double membrane that encloses the nucleus separating its contents from the cytoplasm.

Nucleolus – appears as a mass of densely stained granules and fibres

• protein subunits of ribosomes are made here before being exported into cytoplasm for assembly

Ribosomes – organelles that carry out protein synthesis

• 2 types:

o  Free ribosomes – suspended in the cytoplasm

o  Bound ribosomes – are attached to the outside of the endoplasmic reticulum or nuclear envelope

Endoplasmic Reticulum – an extensive network of membrane-covered channels that transport materials made in the cell, is connect to the nucleus

Golgi Apparatus – flattened sacs (looks like a stack of pita bread) that sorts and packages proteins and other molecules for transport out of the cell.  Unlike the ER, the sacs are not interconnected

Lysosomes – consist of digestive enzymes enclosed in a membranous sac which help to break down ingested substances to be released to the cell as nutrients

Mitochondria – organelle with membranes where energy is released form glucose to fuel cell activities.

Chloroplasts – photosynthesizing organelles, convert light energy to chemical energy (sugars).  Found in plant cells only

Cell Wall – tough rigid structure that lies outside plant cell’s membrane.  Protects plant cell and maintains shape of plant cell.

Cell Membrane: separates the inside of the cell from the outside environment and controls the flow of materials into and out of the cell

Cytoplasm: includes the cytosol (liquid part), organelles and other life-supporting materials

Vesicles: membrane-covered sacs that transport and/or store materials inside the cell.  Also help materials cross the cell membrane to enter or leave cell

Vacuoles: contain water and other materials.  Used to store or transport smaller molecules.  Plant cells have 1 large vacuole animal cells have many small vacuoles

Cytoskeleton: Helps cell maintain its structure and provide tracks for vesicles and organelles to move.  Made of filaments and tubules that provides a framework for the cell