Transcript Cell Structure - Industrial ISD

Cell Structure
https://www.youtube.com/watch?v=gFuEo2ccTPA&feature=youtu.be
Measuring Cell Structures
 1. Measurement taken by scientists are
expressed in Metric Units. The official
name of the metric system is
International System of Measurements.
 The metric system is based on powers
of 10.
fill in the metric chart.
Unit
Prefix Metric equivalent Real life equivalent
Kilometer (km)
Kilo-
1,000 m
Meter (m)
-------
1 m (SI base Unit) A little more than a yard
Centimeter (cm)
Centi-
0.01 m
About half the diameter of a penny
Millimeter (mm)
Milli-
0.001 m
About the width of a pencil tip
Micrometer (um)
Micro- 0.000001 m
About the length of a bacterial cell
Nanometer (nm)
Nano- 0.000000001 m
About the length of a water molecule
About 2/3 of a mile
Types of Microscopes
 1. Compound Light Microscope
The most powerful Light microscopes can
magnify up to 2000X.
 2. Electron Microscope
Electron microscopes can magnify up to
200,000X.
 Transmission Electron Microscopes
(TEM) reveal internal details.
 Scanning Electron Microscopes (SEM)
shows 3-D images of surface.
Eyepiece
Body Tube
Revolving
Nosepiece
Objectives
Arm
Stage Clip
Stage
Course
Adjustment
Fine Adjustment
Base
Diaphragm
Light
 Eyepiece – lens closest to the viewers
eye
 Body Tube – directs light from the
objective to the eye
 Revolving nosepiece – hold the
objectives
 Arm – holds the base of the microscope
with the objectives and eyepiece
 Stage Clips – hold the slide in place
 Stage – supports the slide
 Course Adjustment – used to bring an object
into focus under LOW power
 Fine Adjustment – used to fine tune the focus
under LOW and HIGH power
 Base – holds the light source, connects to the
arm to hold the other parts of the microscope
together
 Objective – more magnification of the
objective
 Light source – light source
 Diaphragm – controls the amount of light that
travels through the specimen
Levels of Organization
 Organism
 Organ System
 Organ
 Tissue
 Cells
 Atoms (Chemical)
I. Looking at Cells
 A. Scientists only became aware of
cells after the invention of the
microscope.
 1. 1665:Robert Hooke observed cork cells
and called them “little boxes”.
1675:Anton van Leeuwenhoek used a
microscope and observed pond water. He
discovered many living creatures.
Cell Theory
 A. Whose observations helped form the
CELL THEORY?
 1838- Mattias Schleiden concluded that
cells make up every part of the Plant.
 1839- Theodor Schwann concluded that
animals are made up of cells.
 1858- Rudolph Virchow determined that
cells only come from other cells.
3 parts of the Cell Theory
 1. All living things are made up of one or
more cells.
 2. Cells are the basic units of structure and
function in organisms.
 3. All cells arise from existing cells.
CELL SIZE
 Small cells function more efficiently
than large cells.
 How many cells are our bodies made up of?
100 trillion
 The advantage of cells being smaller is that
substances that enter or leave a cell
must cross that cell’s surface; if the cell
is small they can exchange substances
more readily than large ones.
Relationship between Surface area and
Volume
Common Features of Cells
 Cell Membrane- outer boundary of cell
 Function- regulates what enters and leaves
the cell
 Made up of- phospholipids and proteins
 Cytoplasm- fills the cell; cell parts are
suspended in this
 Function- same as above
 Made up of- water and salts
 Cytoskeleton- a system of microscopic
fibers
 Function- provides framework, shape and
support
 Made up of- protein fibers
 Ribosomes- proteins are made here
 DNA- found in the nucleus
 Function- provides instructions for making
proteins, regulates cell activities
 Made up of- nucleotides
Prokaryotes
 Smallest and simplest cells.
 Prokaryote- is a single-celled organism that
LACKS a nucleus and other compartments
 They were the only organisms on Earth for 2
billion years. They are very simple and
small. The familiar prokaryotes that cause
infection and cause food to spoil are
commonly called Bacteria.
Characteristics of Prokaryotes
 They can live everywhere.
 They can cause infection in humans and
grow and divide very rapidly.
 Some do not need oxygen to survive.
 Some can make their own food.
 Prokaryotic cells have cytoplasm, cell wall,
ribosomes, cell membrane & DNA (circular).
Some have flagella for movement.
 Some prokaryotic cell walls are surrounded
by a capsule that enables the cell to cling to
almost anything.
.
Flagellum
Capsule
DNA
Plasma
Membrane
Cell Wall
Ribsomes
Eukaryotic Cells
 A eukaryote is an organism whose
cells have a nucleus.
 Organelle-parts of the cell that
carry out specific activities
 Nucleus-internal compartment that
holds DNA
Function- controls cells activities
 Cilia-short hair-like structures
 Function-used for movement
 Cytoskeleton- provides interior framework
 Function- support and shape of the cell
 Made up of- protein fibers: microfilaments,
microtubules, intermediate fibers
Cell Membrane
 Cell Membrane- selective
permeability (barrier)
 Made up of- phospholipids and
proteins
 Draw a picture below of the Cell
Membrane- Phospholipid and a
Lipid bilayer:
Membrane Proteins
 Serve many roles including: as markers;
as receptors to recognize and bind to
substances; as enzymes; as transport
proteins to move substances across the
membrane
Cell Organelles

The Nucleus
–
–
–
–
Contains Hereditary information- DNA & RNA
RNA- made in nucleus; used to make proteins
DNA- wound tightly into chromosomes
Humans have 46 chromosomes. Garden peas
have 14 chromosomes.
Endoplasmic Reticulum-system of
internal membranes
 Function- moves proteins and other
substances through the cell
 Made up of- lipid bilayer & embedded proteins
 Rough ER- contains ribosomes
 Smooth ER- (lacks ribosomes)-makes lipids
and breaks down toxins
 C. Golgi Apparatus- flattened membranebound sac
 Function- package and distribution center
(UPS)
 Made up of- proteins
 D. Lysosomes- vesicles that bud off of
Golgi Apparatus
 Function-contains cell digestive enzymes
 They are present in plant cells just fewer than
are found in animal cells.
 E. Mitochondria- “MIGHTY
MITOCHONDRIA”-site of cell metabolism
(more mitochondria=more energy)
 Function-makes energy ATP for the cell
 Made up of- 2 membranes-inner is folded out
and outside is smooth.
 F. Centrosome and Centrioles
 Function- aid in cell division. Attaches to
DNA to help divide it between the two
cells
 Made up of- microfilaments, microtubules,
protein
 They are not found in plants cell
F. Structures of Plant Cells-------3 structures found only in PLANT
CELLS.





1. Cell Wall- surrounds the cell membrane
Function- support & maintains shape of the cell
Made up of- proteins, carbohydrates->cellulose
2. Chloroplasts- found in plant cells as well as algae
Function-use light energy to make
Carbohydrates ->glucose (sugar)
 Made up of- 2 membranes; has own DNA
 3. Central vacuole- takes up most of a plant cell’s
volume
 Function-stores water ,nutrients, wastes (when full cell
wall is rigid)