TVMS 2016-17
th
7 Grade
Timm - Ripple
Cells Review Preview
Topics
• Characteristics of living things
• (6)
• Life from life (Redi’s experiment)
• Level of life
• Cell theory
• Common structures and functions
• Plant vs animal
• Respiration / photosynthesis
• Hierarchy (cells, tissues, organs, systems, body)
Six characteristics of all living things are:
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Cellular organization
Contain similar chemicals
Use energy
Grow and develop
Respond to their surroundings
Reproduce
Reproduction
Produce offspring that are
similar to the parents.
Life Comes From Life
Spontaneous Generationmistaken theory that living
things arise from nonliving
things.
Experiments to disprove spontaneous
generation.
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Francesco Redi
Flies do not spontaneously arise
from decaying meat.
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Louis Pasteur
Spontaneous generation does not
occur with bacteria.
Redi’s Experiment
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Manipulated (independent
variable) was the covering on the
jar.
Pasteur’s Experiment
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Manipulated (independent
variable) was boiling the broth in
one flask.
The Needs of Living Things
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Energy
Water
Living space
Stable internal conditions (homeostasis)
Organisms use food as their source of energy.
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Autotrophs- (auto means self;
troph means feeder ) organisms
that make their own food.
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Heterotrophs- (hetero-means
other) organisms that cannot
make their own food.
The Cell Theory
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All living things are composed of cells.
Cells are the basic unit of structure and function in living things.
All cells are produced from other cells.
Cell Theory
• All living things are made up of cells.
• Cells are the smallest working units of all living things.
• All cells come from preexisting cells through cell division.
Definition of Cell
A cell is the smallest unit that is
capable of performing life
functions.
Examples of Cells
Amoeba Proteus
Plant Stem
Bacteria
Red Blood Cell
Nerve Cell
Two Types of Cells
•Prokaryotic
•Eukaryotic
Prokaryotic
• Do not have structures
surrounded by membranes
• Few internal structures
• One-celled organisms,
Bacteria
http://library.thinkquest.org/C004535/prokaryotic_cells.html
Eukaryotic
• Contain organelles surrounded by membranes
• Most living organisms
Plant
http://library.thinkquest.org/C004535/eukaryotic_cells.html
Animal
Cell Size
Cell Structure
& Function
http://koning.ecsu.ctstateu.edu/cell/cell.html
“Typical” Animal Cell
http://web.jjay.cuny.edu/~acarpi/NSC/images/cell.gif
“Typical” Plant Cell
http://waynesword.palomar.edu/images/plant3.gif
Cell Parts
Organelles
Surrounding the Cell
Cell Membrane
• Outer membrane of cell
that controls movement
in and out of the cell
• Double layer
http://library.thinkquest.org/12413/structures.html
Cell Wall
• Most commonly found in plant
cells & bacteria
• Supports & protects cells
http://library.thinkquest.org/12413/structures.html
Movement Across the Plasma Membrane
• A few molecules move freely
– Water, Carbon dioxide, Ammonia, Oxygen
• Carrier proteins transport some molecules
– Proteins embedded in lipid bilayer
– Fluid mosaic model – describes fluid nature of a lipid bilayer
with proteins
Membrane Proteins
1. Channels or transporters
– Move molecules in one direction
2. Receptors
– Recognize certain chemicals
Membrane Proteins
3. Glycoproteins
– Identify cell type
4. Enzymes
– Catalyze production of substances
Cell Walls
• Found in plants, fungi, & many protists
• Surrounds plasma membrane
Cell Wall Differences
• Plants – mostly cellulose
• Fungi – contain chitin
Inside the Cell
Nucleus
• Directs cell activities
• Separated from cytoplasm by nuclear
membrane
• Contains genetic material - DNA
Nucleus
• Control center of cell
• Double membrane
• Contains
– Chromosomes
– Nucleolus
DNA
• Hereditary material
• Chromosomes
– DNA
– Protiens
– Form for cell division
• Chromatin
Nuclear Membrane
• Surrounds nucleus
• Made of two layers
• Openings allow material to
enter and leave nucleus
http://library.thinkquest.org/12413/structures.html
Nuclear Envelope
• Separates nucleus from rest of cell
• Double membrane
• Has pores
Chromosomes
• In nucleus
• Made of DNA
• Contain instructions for traits &
characteristics
http://library.thinkquest.org/12413/structures.html
Nucleolus
• Inside nucleus
• Contains RNA to build
proteins
http://library.thinkquest.org/12413/structures.html
Nucleolus
• Most cells have 2 or more
• Directs synthesis of RNA
• Forms ribosomes
Cytoplasm
• Gel-like mixture
• Surrounded by cell membrane
• Contains hereditary material
Endoplasmic Reticulum
• Moves materials around
in cell
• Smooth type: lacks
ribosomes
• Rough type (pictured):
ribosomes embedded in
surface
http://library.thinkquest.org/12413/structures.html
Ribosomes
• Each cell contains thousands
• Make proteins
• Found on ribosomes & floating
throughout the cell
http://library.thinkquest.org/12413/structures.html
Mitochondria
• Produces energy through
chemical reactions –
breaking down fats &
carbohydrates
• Controls level of water and
other materials in cell
• Recycles and decomposes
proteins, fats, and
carbohydrates
http://library.thinkquest.org/12413/structures.html
Mitochondria
• Have their own DNA
• Bound by double membrane
Mitochondria
• Break down fuel molecules (cellular respiration)
– Glucose
– Fatty acids
• Release energy
– ATP
Golgi Bodies
• Protein 'packaging
plant'
• Move materials within
the cell
• Move materials out of
the cell
http://library.thinkquest.org/12413/structures.html
Golgi Apparatus
• Involved in synthesis of plant cell wall
• Packaging & shipping station of cell
Golgi Apparatus Function
1. Molecules come in vesicles
2. Vesicles fuse with Golgi membrane
3. Molecules may be modified by Golgi
Golgi Apparatus Function (Continued)
4. Molecules pinched-off in separate vesicle
5. Vesicle leaves Golgi apparatus
6. Vesicles may combine with plasma
membrane to secrete contents
Lysosome
• Digestive 'plant' for
proteins, fats, and
carbohydrates
• Transports undigested
material to cell
membrane for removal
• Cell breaks down if
lysosome explodes
http://library.thinkquest.org/12413/structures.html
Lysosomes
• Contain digestive enzymes
• Functions
– Aid in cell renewal
– Break down old cell parts
– Digests invaders
Vacuoles
• Membrane-bound sacs for
storage, digestion, and waste
removal
• Contains water solution
• Help plants maintain shape
http://library.thinkquest.org/12413/structures.html
Vacuoles
• Membrane bound storage sacs
• More common in plants than animals
• Contents
– Water
– Food
– wastes
Chloroplast
• Usually found in plant cells
• Contains green chlorophyll
• Where photosynthesis takes
place
http://library.thinkquest.org/12413/structures.html
Plant cells
Cork cell
Onion cell
Elodea cells
“Typical” Plant Cell
http://waynesword.palomar.edu/images/plant3.gif
Plant Cell
Animal Cells
Blood cells
Frog blood cells
Cheek Cells
“Typical” Animal Cell
http://web.jjay.cuny.edu/~acarpi/NSC/images/cell.gif
Animal Cell
Chloroplasts
• Derived form photosynthetic bacteria
• Solar energy capturing organelle
Photosynthesis
• Takes place in the chloroplast
• Makes cellular food – glucose
Levels of
Organization
SONGS
ATOM
MOLECULE
MACROMOLECULE
ORGANELLE
CELL
TISSUE
ORGAN
SYSTEM
ORGANISM
ATOMS
• Smallest part of matter
• NON-living
Molecules
• 2 or more bonded atoms
• Form compounds
• NON-living
Macromolecule
• Very large molecules
• Proteins, fats, carbohydrates, nucleic
acids
• NON-living
Organelles
• “Tiny organs”
• Made of macromolecules
Cell
• Made of organelles
• Basic unit of structure & function
• LIVING
Tissue
• The same kind cell working together
• Living
Organs
• Tissues that work together
• Living
Systems
• Organs that work together
• Living
Organism
• Entire living things
(organisms)
• Usually made of
systems
• May be a single cell
• Living
Population
• Same type of
organism living
together
Community
• Several populations living together
• Population interact
Ecosystem
• A biotic (living) community plus the
abiotic (nonliving) features
Biome
• Similar ecosystems on earth together
Biosphere
• Whole living layer around the globe
• Includes abiotic features
http://people.hofstra.edu/geotrans/eng/ch8en/conc8en/envisys.html
Atom
Molecule
Macromolecule
Organelle
Cell
Tissue
Organ
System
Organism
Population
Community
Ecosystem
Biome
Biosphere
Cellular organization
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Cells
Tissue
Organs
Organ systems