Bio: Cell Theory and Organelles

Robert Hooke (1665)

Robert Hooke (1665)

• coined the word "cell"

• found that they appeared as tiny compartments or small fitted rooms

Anton van Leeuwenhoek (1676)

• observed tiny living organisms

• called them "animalcules"

• first observed red blood cells of animals and sperm cells

Robert Brown (1831)

observed and coined "nucleus" inside the cells

Matthias Schleiden (1838)

all plant parts are made up of cells

Theodor Schwann (1839)

all animal tissues are composed of cells

Rudolf Virchow (1858)

• all cells come from pre-existing cells

• "omnis cellila e cellula"

Three Postulates of Cell Theory

1. all living organisms are composed of one or more cells

2. the cell is the basic unit of life

3. all cells come from preexisting cells

Prokaryotic Cells

single-celled microorganisms whose cells lack a nucleus and other organelles

Eukaryotic Cells

multicellular cell or organism that possesses a clearly defined nucleus

Plant Cell Structure

similar in shape (mostly rectangular or cube shaped), larger than animal cells in size,

Animal Cell Structure

shape and size vary greatly from irregular to round shapes defined by function

Three Roles of Cells

1. produce energy

2. produce protein

3. reproduce / make more cells

Organelles that Produce Energy

mitochondria, cell membrane, vacuole and vesicle, lysosome

Organelles that Produce Protein

Nucleus, Ribosome, Endoplasmic Reticulum, Golgi Apparatus

ATP

adenosine triphosphate (ATP), energy-carrying molecule found in the cells of all living things

cell membrane

• separates cell from outside

• controls what enters or leaves the cell

phospholipid

makes the cell membrane; composed of phosphate head and lipid tail (composed of fatty and phosphoric acid)

cell membrane

recognizes signals and allows communication between cells

cytoplasm

jelly-like material holding organelles in place, full of protein

vacuole and vesicles

• responsible for transporting materials around the cell

• food and water storage

mitochondria

"powerhouse of the cell" makes ATP energy from cellular respiration (is double membraned)

ATP Formula

sugar + O₂ → ATP

lysosome

• responsible for food digestion

• garbage disposal and recycling

chloroplasts

make energy and glucose from sunlight through photosynthesis

Central Dogma of Biology

Nucleus: DNA → RNA → Ribosome → Protein → Vasicle → Golgi Apparatus → Vesicle → Cells

Nucleus

• control center of the cell

• protects DNA

DNA

contains genetic code, and instructions for building proteins

Structure of Nucleus

contains: nuclear membrane, nucleolus (ribosome factory), chromosomes

ribosomes

protein factories, some are free in the cytoplasm, some are attached to ER

Centrioles

help coordinate cell division in animal cells