L3 Biology Chapter 1 Section 2 Cell Structure L3 Biology Chapter 1 Section 2

What is a cell? Smallest unit of life that can carry out all the functions of a living thing. Various sizes and shapes Organism- living thing Unicellular multicellular

Microscope Development 1665 – Robert Hooke named cell 1674 – Anton von Leeuwenhoek - looked at cells in pond water and blood and published his observations

Cell Theory Developed 1838 – Schleiden – all plants are made of cells 1839 – Schwann – all animals are made of cells 1855 – Virchow – all cells come from pre-existing cells

Modern Cell Theory Cells are the basic units of all life. All organisms are made of one or more cells All cells come from pre-existing cells

Microscopes Hand lens Compound light microscope

Cells from Labs:

Electron Microscope Uses electrons for energy source Specimen must be killed Transmission electron microscope (TEM) – take pictures of slices of specimen

TEM Examples

Scanning electron microscope (SEM) – take pictures of surface of specimen

SEM Examples

Types of Cells Prokaryotic Eukaryotic Simple cell No membrane-bound organelles Chromosome not contained in nucleus Small cells Ex - bacteria Eukaryotic Complex cell Membrane-bound organelles Chromosomes contained in nucleus Larger cells Ex – all other organisms

BASIC CELL STRUCTURES Cell Membrane – Double layer of lipids (fats) that lets stuff in and out of cell

Cytoskeleton Cell support Anchors organelles Transports materials Helps cell move

Nucleus Control center of cell Contains Chromosomes Humans have 46 in each cell Made of DNA - control heredity - control protein synthesis Surrounded by double membrane – nuclear membrane

Cell Membrane

Nucleolus Within nucleus May be more than one Makes ribosomes Rich in RNA

Cellular Organelles – small, specialized structures in the cell

Ribosomes Make proteins Some are free, some are attached to endoplasmic reticulum. Smallest organelles

Endoplasmic Reticulum (ER) Transports materials through the cytoplasm Rough ER – have ribosomes attached Transport proteins Helps make membranes Smooth ER – no ribosomes attached Makes lipids Detoxifies wastes

Golgi Body Packages cell secretions Makes lysosomes Contain digestive enzymes for breaking down food in food vacuoles and old, worn out structures – ex – sperm tail after fertilization.

Site of cellular respiration – food is broken down to release energy. Mitochondrion Site of cellular respiration – food is broken down to release energy.

Structures used for Movement Cilia Flagella

Eukaryotic Cells include Plant and Animal Cells ANIMAL CELL STRUTURE

Plant cells have some parts that animal cells don’t Cell Wall Central Vacuole Plastids Chloroplasts Leukoplasts chromoplasts

What animal cells have that plant cells don’t Centrioles – function during cell division Lysosomes – contain digestive enzymes

Now you are ready to have a test on parts of a cell and what they do: Make a chart like below: Cell part appearance function Cell membrane Cytoplasm Etc.

Feature Prokaryotic Eukaryotic In addition, you should be able to name some differences between prokaryotic and eukaryotic cells Make a chart like this: Feature Prokaryotic Eukaryotic

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