Post on 16-Mar-2018
Cells
What is a cell?● All living things have cells whether it is one or many!● Therefore, a cell is the basic unit of all life.● The invention of the microscope was pivotal
to the study of cell biology.
(*Know the parts of the microscope!)
Important Cell Scientists:Anton Von Leeuwenhoek First to see bacteria and protists (mid-1600s)
Robert Hooke Looked at thin slices of cork under microscope thought little boxes (cell walls) looked like the rooms they lived in, in the monastery, so named them "cells" (mid-1600s).
Cell Scientists cont’d...Matthias Schleiden German scientist who concluded that all plants are made of cells. (1838)
Theodor Schwann German scientist who concluded that all animals are made of cells. (1839)
Rudolf Virchow Proposed that all cells come from pre-existing.
The Cell Theory:A theory created by the combination of all the cell scientists’ work.
The 3 parts of cell theory:
1. All living things are made of cells
2. Cells are the basic unit of life
3. All cells come from preexisting cells
Prokaryotic Cells:Single celled organisms (unicellular) found in most environments. They are the simplest of all organisms.
Characteristics:
● No nuclear membrane● DNA is loose in the cytoplasm● No "membrane bound" organelles ● Does have cell membrane, ribosomes, DNA, cytoplasm, and cell wall.
Examples: E. coli, staphylococcus (MRSA), and streptococcus (strep throat)
Eukaryotic Cells:More complex than prokaryotes. They can be unicellular or multicellular.
Characteristics:
● Nuclear membrane surrounding nucleus● LOTS of "membrane-bound" organelles (Ex: mitochondria, chloroplast, nucleus,
etc.)
Examples: algae, yeast, flowers, humans
**Remember the saying “Pro No Eu do”!
Plant Cells (Eukaryotic)Living things that belong to the Kingdom Plantae are called plants.
Characteristics
● Box shaped and green● Multicellular● AUTOTROPHS (photosynthesis, chloroplasts w/ chlorophyll)● Cell walls made of cellulose● Large central vacuole
Examples: moss, trees, ferns, and daisies
Animal Cells (Eukaryotic)Living things that belong to the Kingdom Animalia are called ANIMALS.
Characteristics:
● Multicellular● HETEROTROPHS● No cell wall● Small vacuole or none● Round● Have centrioles
Examples: really cute llamas, fish, and YOU!
Organelles:An organelle is a tiny part of a cell that carries out a specific function. They work together just as your organs work together.
Organelles found in ALL cells (pro and eu): ● Cell membrane● Cytoplasm● DNA● Ribosomes
Organelles found in plant cells:● Cell wall (in prokaryotic cell too)● Chloroplasts● Central Vacuole
Organelles found in animal cells:● Centrioles
NucleusStructure:
● Contains DNA (chromatin).● Surrounded by the nuclear
envelope.● Separates genetic material
from rest of cell (contained).
Function:
● Helps control cell activities.● “Cell headquarters”.
CytoplasmStructure:
● Jelly-like substance that fills the cell.
● The portion of the cell outside of the nucleus.
Function:
● Contains all the organelles.● Chemical reactions occur here.
MitochondriaStructure:
● Folded inner membrane to increase surface area for energy production during cellular respiration.
Function:
● Creates energy (ATP) for the cell.
● The “powerhouse” of the cell.
RibosomesStructure:
● Made up of RNA and protein.● Can be free floating or attached
to the endoplasmic reticulum.
Function:
● Synthesizes proteins for the cell.
● Protein-making “factory”.
CentriolesStructure:
● Made of small tubes.
Function:
● Help separate the chromosomes during cell division.
● Only in animal cells.
Cell WallStructure:
● Made of cellulose (polysaccharide).
Function:
● Rigid structure used to support and protect plants and prokaryotic cells.
*Not made of cellulose in prokaryotic cells.
Cell MemebraneStructure:
● Lipid Bilayer (2 layers of lipids → phospholipids!) that surrounds the cell.
Function:
● Controls what enters and leaves.
● Maintains homeostasis.
VacuoleStructure:
● Membrane bound sac.
Function:
● Stores food, water, and waste.
● One large central vacuole in plants.
● Animals have small vacuoles.
ChloroplastStructure:
● Outer membrane with inner membrane stacks.
● Contain the pigment chlorophyll.
Function:
● Produces food (glucose) for the cell through photosynthesis.
LysosomeStructure:
● A sac that contains enzymes.
Function:
● Digest/break down old cells or cell parts.
Prokaryotic vs. Eukaryotic
Prokaryotic vs. Eukaryotic
● Smaller/simpler● No nucleus ● No “membrane bound”
organelles● DNA loose in cell ● Bacteria
● Larger/complex● Multicellular ● Nucleus - DNA contained● Nuclear membrane● Many “membrane bound”
organelles○ Mitochondria,
vacuoles, chloroplasts
● Plants, animals, fish
Unicellular,cell membrane, ribosomes, DNA, cytoplasm, cell wall*
Animal vs Plant Cell
Animal vs Plant Cell
● Round● Heterotrophs● Small vacuoles● Have centrioles● Lysosomes
● Box shaped● Green● Autotrophs● Have cell walls● Large vacuoles● Chloroplasts
EukaryotesMulticellularCell membraneNucleusRibosomesMitochondria Cytoplasm