Download Welcome to the Living Environment

Cells and
life
What do all living things have in
common?
 There
are 8 characteristics that all
things have in common.
The characteristics of life:
1.
Living things are
made up of cells.
2. Living things reproduce.
3. Living things are based on a
universal genetic code.
4. Living things grow and develop.
5. Living things obtain and use
materials and energy.
6. Living things respond to their
environment.
7. Living things maintain a stable
internal environment.
8. As a group, living things change over time (evolve).
Life Processes video
What exactly is a cell?

Cell: a collection of living matter enclosed
by a barrier (membrane) that separates
the cell from its surroundings.

Cells are the smallest unit of life.
Cell Theory
There are 3 components of
the Cell theory:
Component #1

All living things are composed
(made of) cells.
Component #2
2. Cells are the basic units
of structure and function
in living things.
Component #3
3. New cells are
produced from
existing cells.

Exceptions to the cell
theory –
 1. Viruses:

they are able to reproduce
only within a living cell.

2. Mitochondria and
Chloroplasts


A) each contain their own DNA
B) are able to reproduce by
themselves.
Cells are broken into 2 groups:
• 1. Prokaryotic
2. Eukaryotic
Prokaryotic
Found only in
Kingdom
Monera
(bacteria)
No True Nucleus (has
DNA but not in a
nucleus)
No membrane bound
organelles
(ex: mitochondria)
Eukaryotic
Found in Kingdoms
Protista,
Fungi,
Plantae and
Animalia
True Nucleus:
(has DNA in a nucleus)
Contains cytoplasm and
has membrane bound
organelles
Pics of eukaryotic and prokaryotic
cells
Cells are Freakin Amazing:
Each cell is capable of carrying out all of
the life functions.
Each cell has the same exact DNA and
all the directions to make you (the
whole organism)
But Cells vary in size, shape, structure
and function.
How can this be?
lung cell
brain cell
The DNA has thousands of different genes.
 Each gene is a set of instructions.
 For example, you have a gene for eye color.
 That gene has directions to create your blue
eyes.
 Every cell in your body (trillions of them) has
this gene


Every cell has the same exact genes but
some genes can be turned off and some
on. (like a light switch)
A heart cells has different genes turned on
and off, than a brain cell.
 The heart and brain cell have all the same
genes, but vary in which one are turned on
and off.

Components of Living Things
Cell Structure
Cells have particular structures or
organelles that perform specific jobs.
 Organelle: specialized structure that
performs the life activities within the cell.
 Organelles are just like organs such as the
heart and lungs
 The are the organs of the cell.

Cell Organelles include:
1.
Nucleus:

Structure:
surrounded by a semi permeable nuclear
membrane with pores.
Lets things in and out


Nucleus: Function

The “brains” of the cell; directs cell activities
and contains genetic material called
chromosomes that are made of DNA.
 Contents
of the nucleus:
 A) nucleolus –made up of DNA, RNA and
protein.
 Ribosomes are made here in the nucleoli

B) chromatin – long, threadlike strands of
DNA,
This is the hereditary material of the cell.
2. Mitochondria
Structure:
 hot-dog shaped
 Has a double membrane
(outer and inner).
 Inner is call crystae:
Most chemical reactions
occur here.

Mitochondria function:

Known as the power house: Why?

Make energy in the form of ATP using food
we eat and oxygen we breath.
What is this process called?
 Cellular respiration is the process in which
ATP is made in the mitochondria.

most cell contain between 300 and 800
Muscle cells have thousands of them.
Why do muscles cells need more
mitochondria?
___________________________________
____________________________________
____________________________________
Remember that mitochondria have their own DNA
3. Ribosomes
Structure:
Tiny organelles found on ER and free in
cytoplasm.
Ribosome function:
proteins are assemble here.
 Amino acids are linked together to form a
long chain, a macromolecule
 Proteins AKA polypeptides.
 What type of bond forms between amino
acids: peptide bond.

4. Golgi Apparatus (Golgi body):



Structure:
Flat folded membranes
usually located near the nucleus.
Golgi Function:
Make, process and
package proteins.
 Then the golgi sends
proteins to their final
destination
 where ever they are
needed by the body

5. Lysosome:
Structure:
 Small sac

Lysosome function
Function:
 Breaks down food in cell using digestive
enzymes
 Also breaks down old organelles

6. Endoplasmic Reticulum (ER):
 Structure:
 fluid filled channels surrounded by membranes
 found throughout the cytoplasm .
ER function
Function
 A) intracellular (within cell) transport:
moves things around cell
B. surface area for biochemical reactions
2 types of ER
1)smooth – no ribosomes attached
2) rough – ribosomes attached
7. Vacuole:
Structure: little sac, kinda looks like a lysosome
Vacuole function
Used for storage, vacuoles usually contain
water or food.
 (Are you are thirsty? Perhaps your
vacuoles need some water!)

8. Cytoplasm:
Structure: region between the nucleus and
the plasma membrane.
Cytoplasm function
Function –
A) holds organelles
B) Site of many chemical reactions
C) has enzymes needed for these
reactions
9. Cell membrane (plasma
membrane)
Structure:
 thin membrane that surrounds the cell.
 It separates in inside from the outside.
Cell membrane function:
Function
 controls transport of materials into & out of
the cell
 therefore maintaining homeostasis within the
cell.
These organelles are found only in plants:
10. Chloroplasts
 Structure
 system of double membranes.
.
Chloroplast function
Use energy from sunlight to create sugar
by photosynthesis
 contain green pigment chlorophyll

 11.



Cell Wall
Structure:
Outer most part of cell
lies outside plasma membrane.
Cell wall function:
supports and protects the plant cell.
 Has pores that allow free passage of
materials.
 the cell wall is not alive and is not
selectively permeable




13. Cilia & Flagella –
Structure:
hair like structures
Function – movement
A) Cilia – usually many present
& are small.
(Ex. Paramecium)
B) Flagella – usually one or
two present & larger.
(Ex. Sperm)
Cell organelles

http://videos.howstuffworks.com/hsw/6009
-understanding-cells-the-organellesvideo.htm
Venn Diagrams
Section 7-2
Prokaryotes
Eukaryotes
Cell membrane
Ribosomes
Cell wall
Animal Cells
Lysosomes
Go to
Section:
Plant Cells
Cell membrane
Ribosomes
Nucleus
Endoplasmic reticulum
Golgi apparatus
Vacuoles
Mitochondria
Cytoskeleton
Cell Wall
Chloroplasts
Nucleus
Endoplasmic reticulum
Golgi apparatus
Lysosomes
Vacuoles
Mitochondria
Cytoskeleton
Parts of a plant and animal cell.
Create your own cell.
Organization of Living things
1. cells

2. tissues

3. organs

4. organ systems

5. whole organisms
Organizational Levels of life
Living things have different levels of
organization.
 Cell: The simplest level of organization
 Tissue: A group of cells with a similar
function.
 Organs: Groups of tissues working together
to perform a common function.
 An example of this would include the
nervous, muscle, and other tissues which
make up the heart.

Organizational Levels
Organ System: Groups of organs working
together to perform a common function
 The blood vessels, blood, and the heart
are organs which work together to form
the circulatory system.
 Whole Organism: Many different systems
function together to allow a complex
organism to function.

Levels of Organization
Section 7- 4
Muscle cell
Go to
Section:
Smooth muscle tissue
Stomach
Digestive system
Living vs. Nonliving
Living things carry out almost all the life
processes or activities.
 Non-living things are not able to carrying one
or more of the life processes.
 Metabolism: The sum of the energy used in all
the life processes

Life Processes

Complex organisms
require many different
organ systems to carry
out life activities.
Life Processes include:
1. Digestion breakdown
of food to simpler
molecules which can
enter the cells
• 2. Circulation the movement of materials
within an organism or its cells
• 3. Movement (locomotion) change in
position by a living thing

4. Excretion removal of waste products by
an organism (wastes may include carbon
dioxide, water, and urea in urine and sweat)

5. Respiration process which converts the
energy in food to ATP (the form of energy
which can be used by the cells)
 6. Reproduction the making of more
organisms of one's own kind -- not needed
by an individual living thing but is needed by
its species
 7. Immunity the ability of an organism to
resist disease causing organisms and
foreign invaders

8. Coordination the control of the various
activities of an organism (mostly involves
the nervous system and endocrine glands in
complex animals)

9. Synthesis the production of more complex
substances by combining two or more
simpler substances

It is important to realize that cell organelles
are involved in many of these life processes,
as well as the organ systems of complex
organisms.
Life process video