What did Robert Hooke call the boxes that he observed in cork? Cells

What did Robert Hooke call the boxes that he observed in cork? Cells

Why should I care?

So, what is a cell? Smallest functional unit that can support life A bacterium is only one self-sustaining cell You are made up of trillions of interdependent cells Too small to see without a microscope

Problem? Miss Apgar wants to view a bacterial cell that needs to be magnified 1000 times in order to see it. Her compound light microscope has a 10X ocular lens. Which objective lens should she use to see the bacterium? Where is the ocular lens? Where is the objective lens?

What do we remember about microscope history? Robert Hooke Named the cell Cell Structural and functional unit of life Made sketches of the microscopic world

Anton van Leeuwenhoek Perfected a single lens microscope Examined water and milk Called creatures he saw cavorting wee beasties

Some More History Matthias Schleiden Studied plants Determined that all plants are made of cells Theodor Schwann Studied animals Determined that all animals are made of cells

Some More History Rudolf Virchow German physician Proposed that cells divide to form new cells Used his theory to diagnose patients Father of pathology

Cell Theory - putting their work together All organisms are made of cells It can be one solitary cell or many cells working together The cell is the basic unit of organization in living organisms Even in complex organisms like humans, the cell is the basic unit of life All cells come from pre-existing cells Cells grow and divide, passing genetic information to the next generation of cells

How do we know that cells come from other cells?

Two types of cells Prokaryotic cells Simple interior Considered to be the prototype Eukaryotic cells Complex interior Considered to be the latest update

Prokaryotes Simple interior DNA in central nucleoid region Cellular functions happen in open space Single cell organisms Bacteria Archaea

Inside a Prokaryote The cytoplasm is where cell life takes place DNA is concentrated in the nucleoid region Ribosomes make proteins The Flagellum provides transportation Capsule, cell wall, and cytoplasmic membrane provide protection and support

Eukaryotes Complex interior DNA is neatly packaged and protected by nucleus Organelles perform cellular functions Single and multiple cell organisms Amoebas single celled You are a EU-karyote

4 Kingdoms Animalia Plantae Fungi Protista

Inside a Eukaryote The cytoplasm is where the organelles are located DNA is housed in the nucleus Ribosomes make proteins There are many other organelles each covered by a membrane Each organelle has its own function Cytoplasmic membrane provides protection

Venn Diagram Time turn to page 18!

Prokaryotic Cells Eukaryotic Cells

Your task now Look on page 11 in your packet Read The Origin of the Eukaryotic Cell (pgs 19-20) Answer questions pages 21 and 22 Homework if you do not finish!!

More on the Eukaryote cell Important terminology DNA genetic material Organelle cellular structures that carry out specific functions Means little organ Let s break it down

First up: the plasma membrane

The Cell Membrane The cell membrane is selectively permeable Some things can pass but others can t Cell membranes are made from a phospholipid bilayer

Phospholipid Bilayer Structure Each phospholipid has a polar head and two nonpolar tails Polar head is attracted to water Nonpolar tails are repelled by water Outside of cell Cell membrane Proteins Carbohydrate chains Inside of cell (cytoplasm) Protein channel Lipid bilayer

Phospholipid Bilayer Function Allows some things in and not others Polar molecules do not easily pass H 2 O is an exception because it is small Keeps the outside out and the inside in The plasma membrane is always in motion

Fluid Mosaic Model Fluid Membrane is in motion Membrane is flexible Mosaic There are molecules embedded in the bilayer The scattered arrangement looks like a mosaic

Animal Cells vs. Plant Cells Eukaryotic cell which makes up tissues in animals Lack cell walls and chloroplasts, and have smaller vacuoles. Appears to be circular because of the lack of a rigid cell wall. Eukaryotic cell that makes up plants Cell Wall Chloroplast Large Vacuoles

Animal Cell

Plant Cell

Cell Wall plant cell only Mesh of fibers that surrounds the plasma membrane Protects and supports the cell Made of carbohydrate, cellulose

Cytoplasm Semi-fluid material inside the plasma membrane Consists of cytosol and the cellular organelles (all organelles except the cell nucleus) Cytosol - fluid in which the cellular organelles are suspended

Cytoskeleton Network of long, thin protein fibers provide an anchor for organelles Microtubules-long hollow cylinders that assist in moving substances within the cell Microfilaments-thin threads that give the cell shape and enable the cell to move Cytoskeleton in Red and Green

Nucleus Contains genetic material (DNA) Nuclear envelope Nuclear pores allow substances in and out Nucleolus in center Very dense center

Ribosomes Produce proteins Made of RNA and protein Made in the nucleolus Some float freely in the cytoplasm Others attach to endoplasmic reticulum

Endoplasmic Reticulum Interconnected network of tubules

Two types of Endoplasmic Reticulum Rough ER Where ribosomes attach and make proteins Appear to create bumps and rough areas on the membrane Smooth ER No ribosomes Produces complex carbohydrates and lipids

Golgi Apparatus Modifies, sorts, and packs proteins in sacs called vesicles Vesicles fuse with plasma membrane They release proteins which move through membrane to get outside of the cell

Vacuoles Temporary storage for materials in the cytoplasm Store, transport, or digest food and waste Plant cells 1 large vacuole Animal cells several little vacuoles

Lysosomes Vesicles that contain digestive enzymes to digest excess or worn-out organelles and food particles They also digest bacteria and viruses that enter the cell They are built in the Golgi apparatus.

Centrioles Made of Microtubules Found near nucleus Animal Cells only Assembled right before replication Aid in cell replication

Mitochondria Powerhouse Converts organic materials into energy ATP Outer and inner membranes with lots of folds Provides large surface area to break sugar molecule bonds (produce energy)

Chloroplasts- Plant only Capture light energy and convert it to chemical energy through photosynthesis

Photosynthetic Animals 2010 - found an animal that makes proteins essential for photosynthesis Elysia chlorotica sea slug that looks like a giant swimming leaf Stole chloroplasts from algae it eats can live up to 9 months without eating Appears green because of stolen chlorophyll Lives - Eastern coast of the United States and Canada

Cilia and Flagella Cilia- short, hair-like projections Move back and forth like oars on a rowboat Move substances along surface of the cell Flagella- rather long hair-like projections Whip-like motion Both are composed of microtubules Move cells through watery environment

Cell Transportation Passive transport Does not use energy Goes with the concentration gradient 3 types diffusion facilitated diffusion osmosis Active Transport Requires energy Goes against the concentration gradient Endocytosis Exocytosis

Cell Transport Diffusion -net movement of particles from high concentration to low concentration Doesn t require energy because the particle are in motion passive transport Dynamic equilibrium- the overall concentration does not change, but molecules are still moving randomly

What affects the rate of diffusion? What makes molecules move faster? High temperature High Pressure High concentration

Facilitated Diffusion Some ions and molecules can t diffuse across the cell membrane Facilitated diffusion uses transport proteins to help move some molecules across the plasma membrane

Osmosis Osmosis diffusion of water Most cells undergo osmosis because they are surrounded by water

Hyper Hypo Iso tonic Solutions These are comparing words Hypertonic -more solute Hypotonic- less solute Isotonic- same solute as What would happen if you Put a red blood cell in a hypertonic solution Put a red blood cell in a hypotonic solution Put a red blood cell in an isotonic solution

Active Transport Goes from low to high concentration Requires Energy ATP Moves large substances

Endocytosis Endocytosis- moving large substances into the cell

Exocytosis Exocytosis- moving large substances out of the cell