Inside the Cell

Cell Trivia An adult has approx. 60 trillion cells Each of your eyes has 125 million light sensitive cells that are connected to 1 million nerve cells When you donate blood, you give up 5.4 billion cells A square cm of your skin is made up of 155,000 cells. There are 30 billion cells in your brain.

Cells in organisms are specialized to perform particular functions Cell Function Cells in organisms are specialized to perform particular functions Red blood cells transport oxygen throughout the body. Muscle cells contract and relax to move parts of the body. Guard cells control the opening and closing of stomata on the underside of leaves to let in air.

Levels of Organization Cell Tissue Organ Organ System Organism

Inside the Cell Organelles

Inside the Cell Organelles A structure within a cell that performs a specific function.

Prokaryotic and Eukaryotic Two types of cells: Prokaryotic and Eukaryotic Prokaryotic (pro-carry-au-tic) Single cell organisms that do not have a nucleus Bacteria Eukaryotic (you-carry-au-tic) Has a nucleus and organelles Plant and animal cells

1. Cell Membrane Controls what enters and leaves the cell Thin; surrounds the cell

2. Cytoplasm A watery gel material that fills the cell and keeps organelles in place

Mitochondria Converts sugars into energy for the cell (plural for mitochondrion) Converts sugars into energy for the cell Powerhouse of the cell 10

4. Nucleus The nucleus is the largest organelle in a cell Controls cell’s activities The “Brains” of the cell Contains the chromosomes http://hictsci211gene.blogspot.com/

Chromosomes In nucleus Made of DNA Contain instructions for traits & characteristics http://library.thinkquest.org/12413/structures.html

5. Endoplasmic Reticulum Makes, packages and delivers ribosome and lipids Ribosomes are the protein makers Folds and tubes located by the nucleus

Golgi Apparatus (or Golgi Bodies) Modify, sort and package proteins & lipids into vesicles for storage or secretion (for outside of the cell) Flattened membranes stacked together

7. Lysosomes Contains digestive enzymes Breaks down food, viruses, bacteria, old organelles, etc.

8. Vacuoles Stores food, water & wastes Larger in plant cell than in animal cell Helps plants maintain their shape

9. Chloroplast Found only in PLANT cells. Convert light energy into sugars & starch Green, contains chlorophyll

10. Cell Wall Thick, tough layer; surrounds cell Provides support and protection Found only in PLANT cells

Cilia & Flagella Movement Cilia – Many hairlike extensions Flagella - Whip-like tail or long projections