Journey to the World of Cells
Starting Point for Life All living organisms on Earth are divided into pieces called cells. Formed from Proteins Organelles Make larger pieces called Tissues and systems Main purpose to organize Holds a variety of pieces Each cell has a different set of functions
Cell Membrane A membrane is like a plastic bag with some tiny holes Keeps cell pieces and fluid in Keeps out nasty things Acts as protective barrier Holes let some things move in and out
Cell Membrane Structure Protein (around the holes) Some inside layer, and some outside layer Some cross membrane and help with active transport system. Helps move molecules Phospholipid (basic bag) Shaped like a head with a tail Heads like water (hydrophilic) Tails do not like water (hydrophobic) Bilayer (two layers)
Membrane Structure Cell membrane structure lipid bilayer Fluid Mosaic Model Structure of cell membrane discovered in 1970 s Singer and Nicholson
Cell Wall Cell walls are made of specialized sugars called cellulose. Provides a protected framework for a plant cell to survive. Help a plant keep its shape.
Cell Walls in More Than Plants Bacteria Fungi Some Protozoa Not made from cellulose Made from chitin Serves the same purpose but different molecules
Cytoplasm Fluid that fills the cell Cell organelles float in this Contains many different molecules dissolved in solution Enzymes Used to breakdown larger molecules to be used as energy by mitochondria Fatty acids Sugars Amino acids
Nucleus Brain of the cell Controls Eating Movement Reproduction
Nuclear Membrane Surrounds nucleus and its contents Pores and spaces Allow RNA and protein to pass through Keeps chromatin and nucleolus in
Chromatin Carry all the information needed to help a cell grow, live and reproduce Made of DNA Segments of DNA in specific patterns are called genes Chromosomes uncoiled and loose Time to reproduce Condense and wrap up tightly in this state DNA is called a chromosome Usually found in pairs
Nucleolus Looks like a nucleus inside of the nucleus Made of RNA and protein Produces ribosomes
Mitochondria Powerhouses of the cell Act like a digestive system Take nutrients and break them down for energy - cellular respiration
Endoplasmic Reticulum Functions as a packaging system. works closely with the Golgi apparatus, ribososmes, RNA, mrna, and trna. Creates a network of membranes found through the whole cell. Two types Smooth Rough
Ribosomes Build proteins which are used as enzymes or to support other cell functions Found in cytoplasm and attached to the endoplasmic reticulum
Golgi Complex Found in most cells Membranes shaped like pancakes A packaging organelle Gathers simple molecules and combines them to make molecules that are more complex Packages them in vesicles, and either stores them for later use or sends them out of the cell Builds lysosomes In the plant cells may also create complex sugars
Chloroplasts Food producers of the cell. Found in plant cells and some protists. Works to convert the energy of the sun into sugars and oxygen this process is called photosynthesis
Vacuoles Can be found in both plant and animal cell Much larger in plant cell Storage bubbles found in cells Membrane that surrounds fluid Nutrients Waste Plant cells used to store water Can help support the plant
Lysosomes Found in animal-like cells Created by the Golgi Complex Holds enzymes created by cell in endoplasmic reticulum Used to digest things Work when the cell eats food Enzymes breakdown food into proteins and sugars Will even digest other organelles when food is scarce