Cells: The Basic Unit of Life Essential Questions What are cells made of? Where do you find cells?...
-
Upload
martin-norris -
Category
Documents
-
view
219 -
download
0
Transcript of Cells: The Basic Unit of Life Essential Questions What are cells made of? Where do you find cells?...
Cells: The Basic Unit of Life
•Essential Questions•What are cells made of?•Where do you find cells?•Why do cells look different?•How do cells work?
I. Cells – basic building block of life
• Cytology: study of cells• Cyto- having to do with cells• -ology means the study of
• Cytopathology: the study of cellular disease and the use of cellular changes for the diagnosis of disease.
• Cell biology: the study of (normal) cellular anatomy, function and chemistry.
II. Cell History Robert Hooke (1665)
• English Scientist• Looked at a thin slice of
cork (oak tree) through a compound microscope
• Observed tiny, hollow, room like structures
• Called these structures “cells” because they reminded him of the rooms that monks lived in
• He only saw the cell walls because the cork cells weren’t alive
Anton Van Leeuwenhoek (roughly same time as Hooke, 1680?)
• Dutch fabric merchant and amateur scientist
• Looked at blood, rainwater, and scrapings from teeth through a simple microscope (1 lens)
• Observed living cells; called some ‘animalcules’
• Some of those ‘animalcules’ are now called bacteria
• Father of Microbiology
Co-Founders of Cell Theory
Matthias Schleiden (1838)• German
Botanist• Viewed plant
parts under a microscope
• Discovered that plant parts are made of cells
Theodor Schwann (1839)
• German Zoologist
• Viewed animal parts under a microscope
• Discovered that animal parts are made of cells
Rudolf Virchow (1855)
• German physician and politician, known for his advancement of public health
• First to recognize leukemia cells
• Stated that all living cells come from other living cells
• Important contributor to cell theory
III. Cell Theory
• The contributions of Hooke, Van Leeuwenhoek, Schleiden, Schwann and Virchow helped to form the modern cell theory
• 1. All living things are made of cells
• 2. All cells come from other cells
• 3. The cell is the basic unit of organization in organisms
All Living Things…
• Consist of organized parts (cells -> tissues -> organs -> organ systems -> organisms)
• Obtain energy from their surroundings (food chain)
• Perform chemical reactions (metabolize)• Change with time (evolve)• Respond to their environment (adapt)• Reproduce (heredity)
IV. Types of CellsProkaryote
• Simple cell• Lacks a nucleus and
membrane bound organelles• Has circular DNA and
ribosomes• Ex: Bacteria and Archaea are
two domains of prokaryotes
Eukaryote
• More complex cell• Has membrane bound
organelles and nucleus• Possess chromosomes• Ex: are plant and animal
cells
V. Parts of Eukaryotic Cells
Organelle: small, membrane bound structure inside the cell that determines the function of the cell; tiny organs
V. Parts of Eukaryotic Cells, cont.
A. Plasma Membrane – phospholipid bilayer, controls what enters and exits the cell, Gateway
V. Parts of Eukaryotic Cells, cont.B. Cytoplasm- gel-like substance that
surrounds and suspends the organelles, Jell-O of the CellConsists of cytosol- The cytosol is a complex mixture of substances dissolved in water
V. Parts of Eukaryotic Cells, cont.C. Cytoskeleton – network of
microfilaments and microtubules that form the inner structure of the cell, similar to your bones, Skeleton
V. Parts of Eukaryotic Cells, cont.
D. Golgi bodies – set of smooth membranes that form flattened sacs that modify, sort and package proteins for transport to other organelles or exiting the cell FedEx
-small round packages are called vesicles
V. Parts of Eukaryotic Cells, cont.E. Mitchondria – site where cellular
respiration occurs, chemical energy is released from glucose
- Inside folds increase chemical workspace and are called: mitochondrial matrix
- Powerhouse
V. Parts of Eukaryotic Cells, cont.
F. Lysosome – these membrane bound sacs contain enzymes that can digest cellular waste, damaged organelles, and bacteria brought into cell. Can also destroy entire cell
-Suicide sac
V. Parts of Eukaryotic Cells, cont.
G. Ribosomes – tiny, round organelles that are used to make (synthesize) proteins
- workbench
V. Parts of Eukaryotic Cells, cont.H. Endoplasmic Reticulum1. Smooth- works to detoxify cells and
transport materials, MoDOT Highway2. Rough – has ribosomes on it, makes
the phospholipids and proteins, Liver or Highway
V. Parts of Eukaryotic Cells, cont.
I. Vacuole – membrane bound structures that usually hold water and provide structure for the cell
Storage units
V. Parts of Eukaryotic Cells, cont.J. Nucleus – controls all cellular functions
Brain
1. Nuclear Membrane – plasma membrane surrounding and containing the nucleus
2. Nuclear Pores- tiny holes in nuclear membrane that allow RNA to pass in and out of nucleus
3. Chromosomes/Chromatin – Chromatin is DNA free floating, when it prepares for division it coils into chromosomes
4. Nucleolus – site of concentrated DNA in the nucleus
V. Parts of Eukaryotic Cells, cont.
• Outside the cell• Cilia – motile for movement or non-motile for
sensory (below, pink)• Flagella – Single ‘tail’ for movement• Microvilli – are cellular membrane
protrusions that increase the surface area (below, B&W)
V. Parts of Eukaryotic Cells, cont.Animals Only
1. Centrioles – two bundles of nine microtubules, found close to nucleus and lie at 90 degree angle
Plants Only
1. Cell Wall – made from cellulose, outside membrane
2. Chloroplasts – contain stacks of thylakoids called granum & space between stacks is called stroma
3. Plastids – organelles capable of storing food for the plant
4. Chlorophyll – pigment used to capture sun’s energy
5. Chromoplasts- give flowers and fruits their coloring
How are cells organized?
• Specialized cells -> tissue
• Groups of tissue -> organs
• Organs -> organ systems
• Muscle cells -> muscle tissue
• Muscles -> heart
• Heart -> circulatory system
Now just a few more…
• Here are some various types of cells• Notice the different shapes and what type of cell they
are. Do you think this has to do with their function? • Think about it and take the time to notice how perfectly
they are all designed for their jobs.
Human Bone Marrow – Stem Cells
So much debate over these little things that could save countless lives
Nerve CellsThis looks like a lightening storm- fitting because it is an electrical storm of synapses firing electrical signals back and forth for your cells to communicate