• Cell: The basic structural and functional unit of every organism.
• Types of Cells
o Prokaryotic [Archaea & Bacteria]
o Eukaryotic [Animals,
... [Show More] Plants, Fungi]
• All cells have
o Plasma Membrane
o Cytoplasm
o Chromosomes [contain genes] – Made of Chromatin
o Ribosomes [make proteins] – Made of RRNA & Protein
• Prokaryotic Cells [Smaller]
o No nucleus
o DNA in nucleoid
o No membrane bound organelles
• Eukaryotic Cells [Larger]
o DNA in a nucleus bounded by a double membrane
o Bounded Organelles
o Cytoplasm [Fluid between the plasma membrane and nucleus]
• Plasma membrane: a selective barrier that allows sufficient passage of oxygen,
nutrients, and waste to service the volume of every cell.
• The Surface area to Volume ratio of a cell is critical.
• The Nucleus contains most of the DNA
• Ribosomes uses information from the DNA to make Proteins
o Combination of Ribosomal RNA and protein
• Nuclear envelope: A double membrane of lipid bilayer that encloses the nucleus separating it from the cytoplasm
• Pore Complex: Regulates the entry and exit of molecules from the nucleus
• Nuclear lamina: maintains the shape of the nucleus [it’s made of Protein]
• Chromosomes: DNA organized into discrete units.
• Chromatin: This is one DNA molecule associated with proteins
o Euchromatin is loosed chromatin
o Heterochromatin is compact or compressed chromatin
• Nucleolus: The site of Ribosomal RNA synthesis located inside the nucleus
• Ribosomes carry out Protein Synthesis
o In the Cytoplasm [free Ribosomes]
o Outside the endoplasmic reticulum [Bound Ribosomes]
• Endomembrane System
o Nuclear envelope
o Endoplasmic Reticulum
o Golgi apparatus
o Lysosomes
o Vacuoles
o Plasma Membrane
o # Components are either Continuous or connected via vesicles
• Regions of the Endoplasmic Reticulum
o Smooth ER [ Lacks ribosomes]
Makes lipids
Breaks down Carbohydrates
Detoxifies drugs and Poison
Stores Calcium
o Rough ER [Studded with ribosomes]
Distributes transport vesicles
Is a membrane factory for the cell
• Golgi apparatus: Made of flattened sacs called Cisternae
o Modifies product of the ER
o Makes certain macromolecules
o Sorts and packages materials into transport vesicles
• Lysosomes: membranous sac of hydrolytic enzymes that can digest macromolecules
o Hydrolytic enzymes and lysosomal membranes are made by the rough ER
• Phagocytosis: Cells engulfing another cell
• Autophagy: Lysosomes using enzymes to recycle the cells own organelles and macromolecules
• Vacuoles: large vesicles derived from the ER and Golgi apparatus which differ in function by cell
• Types of Vacuoles
o Food Vacuoles: Formed by phagocytosis
o Contractile vacuoles: Pumps excess water out of a cell [in freshwater protist]
o Central Vacuoles: Holds organic compounds and water [in mature plant cells]
• Mitochondria & Chloroplast change energy from one form to another
• Mitochondria: are the sites of cellular respiration, a metabolic process that uses oxygen to generate ATP
o Parts of the mitochondria
Smooth outer membrane
Inner membrane folded into Cristae
• The mitochondrial matrix
• Intermembrane space
• Cristae: this presents a large surface area for enzymes that synthesis ATP
• Chloroplasts: these are sites of photosynthesis found in plants.
• Chloroplast structure includes
o Thylakoids, membranous sacs, stacked to form a granum
o Stroma, the internal fluid
• The chloroplast is one of a group of plant organelles, called plastids
• Peroxisomes are specialized metabolic components bounded by a single membrane
o They produce hydrogen peroxide and convert it to water [Show Less]