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 animal cells: Centrioles Organelles found in plant cells: Cell wall (in prokaryotic cell too) Chloroplasts Central Vacuole

Nucleus Structure: Contains DNA (chromatin). Surrounded by the nuclear envelope. Separates genetic material from rest of cell (contained). Function: Helps control cell activities. “Cell headquarters”.

Cytoplasm Structure: 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.

Mitochondria Structure: 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.

Ribosomes Structure: 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”.

Centrioles Structure: Made of small tubes. Function: Help separate the chromosomes during cell division. Only in animal cells.

Cell Wall Structure: Made of cellulose (polysaccharide). Function: Rigid structure used to support and protect plants and prokaryotic cells. *Not made of cellulose in prokaryotic cells.

Cell Memebrane Structure: Lipid Bilayer (2 layers of lipids → phospholipids!) that surrounds the cell. Function: Controls what enters and leaves. Maintains homeostasis.

Vacuole Structure: Membrane bound sac. Function: Stores food, water, and waste. One large central vacuole in plants. Animals have small vacuoles.

Chloroplast Structure: Outer membrane with inner membrane stacks. Contain the pigment chlorophyll. Function: Produces food (glucose) for the cell through photosynthesis.

Lysosome Structure: 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 Box shaped Round Green Heterotrophs Eukaryotes Autotrophs Have cell walls Large vacuoles Chloroplasts Round Heterotrophs Small vacuoles Have centrioles Lysosomes Eukaryotes Multicellular Cell membrane Nucleus Ribosomes Mitochondria Cytoplasm