Nucleus is the information central, contains DNA
Functions: Cell division, store DNA, RNA, protein synthesis
-RNA transported through nucleur pore
-Nucleus envelope form by 2 bilayers of lipids, each membrane made up of 1 bilayer
- Chromosome made of proteins and DNA
Mitochondria:
Structure: double membrane (outer and inner membrane)
Outer membrane: transport protein called porin, easier for small water soluble molecules to
move in
Inner membrane have many folds to increase the surface area
Matrix: Contains circular DNA, enzymes to produce ATP, ribosomes.
1 micrometer
Inner membrane have many folds to increase the surface area
Functions: Responsible for aerobic respiration as it releases lots of energy, synthesize lipds
Ribosomes:
What it is? -Protein factory -Made of rRNA
Structure: Don’t have membrane, two subunits (large and small)
70s (3 molecules of RNA) , Prokaryotic cell
80s ribosomes ( 4 molecules of RNA), Eukaryotic cell
Function: Read RNA and synthesized protein
Chloroplasts:
-Found in palisade mesophyll and spongy mesophyll
- The mesophyll is tightly packed so that they can increase their SA
Structure:
5-10 micrometer
-Double membrane
-Contains flattened sacs known as thylakoid
-Thylakoids stacked on top of each other to form grana
- These structures are in a matrix called the stroma
Smooth Endoplasmic Reticulum
-Connected to the nuclear envelope
-Large amount located in liver, ovaries and testes cells
-Function: Synthesize lipids, steroid (fats) hormones, detoxified poisons, stores calcium
Golgi Apparatus:
-Consist of flattened membranous sacs called cisternae (6-8), they are held together by
matrix proteins
-Functions: Modifies proteins of rER which transferred by the vesicles.
Creat medium to transport
Cisface and transface
Doesn’t have ribosomes
Shorter and more curve cisternae than ER
Vesicles:
A single membrane with fluid inside
-Used to transport materials inside the cell
-Made from the golgi body
Lysosomes:
-Membranous sac of hydrolytic enzymes that can digest macromolecules
- They can hydrolyze proteins, fats, polysaccharides, and nucleic acids
- Acid environment
- Spherical structure
- Single membrane
- Found a lot in liver to detoxified toxics
-White blood cell needs lysosomes to engulf bacteria
-Functions: Digestive enzymes for endocytosis, autophagocytosis ( lysosomes break down
old organelles or get rid of it) , phagocytosis ( process of bringing the bacteria from outside
to inside), destruct the cell itself. High concentration of enzymes cause this organelle to
stain heavily and hence dark appear dark on micrographs.
Centrioles and microtubules:
500 nm
Cytoskeleton: Network of fibers extending throughout the cytoplasm
Functions: Keep the cell in shape and organize them, anchor them down (they don’t move
around)
Components:
Microtubules – the thickest
Long hollow rods about 25 nm in diameter, 200nm long
Made of a protein called tubulin ( made from alpha tubulin and belta tubulin, they joined
together to become dimers.) many dimers made up protofilament. 13 protofilaments make
up microtubules
-Functions: Shaping the cell, create intracellular transport, separating chromosomes during
cell division, hold all the cell in place, microtubules control the beating of cilia and flagella of
some cells
-Microtubules grow out from a centrosome near the nucleus
Microfilaments are made up of actin,
Function: resisting pulling forces within the cell
Bundles of microfilaments make up the core of microvilli of intestinal cells
Intermediate filaments
Centrioles: Made up of nine triplets of microtubules (only have in animal cell)
2 centrioles made up 1 centrosome ( microtubule-organizing center)