Cell Theory 1.All living organisms are made of one or more cells. 2.The cell is the basic organizational unit of life. 3.All cells come from pre- existing cells. 1.All living organisms are made of one or more cells. 2.The cell is the basic organizational unit of life. 3.All cells come from pre- existing cells.

Visualizing Cells

CELL STRUCTURES

NUCLEUS The control center for all cell activity “the brain” Contains genetic DNA Surrounded by a thin, double nuclear membrane Contains thick protoplasm (rich in protein) called nucleoplasm (contain chromatin materials) The control center for all cell activity “the brain” Contains genetic DNA Surrounded by a thin, double nuclear membrane Contains thick protoplasm (rich in protein) called nucleoplasm (contain chromatin materials)

NUCLEOLUS Found in the nucleus Takes part in protein synthesis (makes ribosome) Found in the nucleus Takes part in protein synthesis (makes ribosome)

CELLULAR MEMBRANE Phospholipids bilayer Keeps all cell structures inside the cell Controls what goes in and what goes out Phospholipids bilayer Keeps all cell structures inside the cell Controls what goes in and what goes out

NUCLEAR MEMBRANE separates the nuclear material from other parts of the cell Not really a solid barrier semi permeable – allows some things in and some things out separates the nuclear material from other parts of the cell Not really a solid barrier semi permeable – allows some things in and some things out

CYTOPLASM Cell materials outside nucleus make up cytoplasm CLEAR THICK JELLY LIKE FLUID Largest component of cell and holds things in place Cell materials outside nucleus make up cytoplasm CLEAR THICK JELLY LIKE FLUID Largest component of cell and holds things in place

CYTOPLASM HOLDS SEVERAL ORGANIZED STRUCTURES IN PLACE IN THE CELL THESE STRUCTURES ARE CALLED: CYTOPLASM HOLDS SEVERAL ORGANIZED STRUCTURES IN PLACE IN THE CELL THESE STRUCTURES ARE CALLED: Each organelle has its own specific role “Little Organs”

Endoplasmic Reticulum Fastens to cell membrane and nuclear membrane Carries materials (nutrients, proteins) through the cell Series of canals or channels (pathways) within the cell Can be either A) SMOOTH ER B) ROUGH ER Fastens to cell membrane and nuclear membrane Carries materials (nutrients, proteins) through the cell Series of canals or channels (pathways) within the cell Can be either A) SMOOTH ER B) ROUGH ER

RIBOSOMES - Small bumps on ER or on cytoplasm - Tiny grainy structures - Small bumps on ER or on cytoplasm - Tiny grainy structures -Contain enzymes that control PROTEIN SYNTHESIS - Builds protein essential for cell growth and reproduction -Called protein factories of the cell

MITOCHONDRIA **Center for respiration in the cell **Releases energy POWERHOUSE OF CELL **Center for respiration in the cell **Releases energy POWERHOUSE OF CELL At least 95% of energy in cell comes from mitochondria

Cristea- inward folds…increaseses surface area

Lysosomes ( suicide sacs) Only one simple membrane Contains enzymes that cause digestion of proteins Breaks down molecules so they can be used for building materials Only one simple membrane Contains enzymes that cause digestion of proteins Breaks down molecules so they can be used for building materials Lysosomes will burst open and break down any dead cells

Several hundred lysosomal structures can be seen in the above phase micrograph.

GOLGI APPARATUS Looks likes stacks of flattened sacs piled up on one another…. These packages then go to the cells surface for export!!! Recieves protein from endoplasmic reticulum

Vacuole Not considered to be an organelle Often found in plants (very large) Not considered to be an organelle Often found in plants (very large) Fluid-filled space that contains water sugar minerals and proteins

Plastids  Found in plants  Some store foods, others act as a chemical factory Types: Chloroplasts – contain green pigment called chlorophyll - traps energy from the sun to make glucose in photosynthesis Leucoplasts – serve as food storehouses main center for storing starch  Found in plants  Some store foods, others act as a chemical factory Types: Chloroplasts – contain green pigment called chlorophyll - traps energy from the sun to make glucose in photosynthesis Leucoplasts – serve as food storehouses main center for storing starch Onion tip root

Cytoskeleton Network of protein fibers supporting cell shape and anchoring organelles Actin Microtubules Intermediate filaments

Interactive cell site