Transcript Regents Intro Unit PP File

Biology
living/once-
“the study of”
living things
What determines if something is living?
There is no single definition of life. However, there is a
list of characteristics by which we determine if
something is living or not.
In order to be considered “living”, you need to display the
potential for all of the following life functions:
1. Nutrition- obtaining materials from the environment
and processing them for use within the
organism.
a. heterotrophs- organisms that consume food (dog,
human)
ingestion- taking in food
digestion- breaking down food
egestion- removal of undigested or
indigestible food ex) corn, fiber,
throwing up
What must an oak tree do to stay alive
that both a fly and a human must also
do?
b. Autotrophs- “auto”= self
“trophic”= nutrition (plants)
*Photosynthesis:
chlorophyll
CO2 + H2O light
enzymes
C6H12O6 + O2 + H2O
2. Transport- the absorption and circulation of materials
within an organism
•a. single-celled organisms (or any cell w/in an
organism… materials are diffused/absorbed
directly across the cell membrane
•b. multi-celled organisms-most cells aren’t in
contact w/the environment so a circulatory
system is needed
3. Respiration- The exchange of O2 and CO2 AND the
release of energy that is stored in food
molecules.(glucose)
•a. anaerobic- does not use oxygen, produces little
energy
•b. aerobic- does use oxygen, produces lots of
energy, more efficient
C6H12O6 + O2
(glucose)
CO2 + H2O + Energy (36 ATP)
4. Excretion- the removal of wastes from cells + from an
organism which were produced during life
processes.
•lungs remove CO2 + H2O
•skin removes H2O, salts + urea
•kidneys remove H2O, salts + urea
•liver removes dead RBCs
5. Synthesis & Assimilationchemical reactions
where large molecules
are built from smaller
ones
The incorporation of these synthesized
molecules into the organism’s body
Ex) when proteins become part of a
body builder’s muscles from a proteinrich diet
“You are what you eat!!!”
6. Regulation- the control & coordination of all life
activities in an effort to maintain
homeostasis (stable internal enviroment)
2 systems involved:
•a. nervous- electrical: brain, spinal cord, nerves
•b. endocrine- chemical: hormones, glands
7. Growth- increase in size and/or number of cells
• you grow in # of cells from infant teen
• an ameba’s 1 cell can increase in size
• requires materials that were synthesized
from the nutrients ingested
8. Reproduction- creating a new organism/cell
~species survival is dependent on reproduction,
individual survival is not
~asexual & sexual
•1 parent,
•identical offspring,
•no variety
•2 parents,
•offspring have a
combination of parents’
traits
Metabolism
the total of all life processes/chemical
reactions working together to keep an organism alive
Homeostasis
The maintenance of a stable internal environment w/in
an organism
ex) maintaining a constant body temperature, blood
sugar level
Homeostasis video
Borderline cases of living things:
Seeds, flower bulbs, viruses, HIV
They display only some of the life functions some
of the time. At other times, they are said to be
dormant (“sleeping”)
More on viruses……..
•contain genetic material but lack other cell
structures to carry out metabolism
•they are not cells and do not fit into any kingdom
•they cannot reproduce without a host cell
…….disruption of homeostasis!!
http://phschool.com/
Enter code cbp-6192
End of notes for Life Function Quiz
Lab safety rap song
How did we discover the cell?
Laser clip
“Intro to
Cell Study”
Microscopes
1. Simple•1 lens
•magnifies 3-10 times
•AKA magnifying glass
2. Compound- (what we use at school)
•2 lenses
•Magnifies 40-400 times
• See diagram
Practice w/this
diagram:
ocular/eyepiece
body tube
nosepiece
objective lens
arm
objective lens
objective lens
stage clips
stage
coarse adjustment
diaphragm
light
fine adjustment
base
3. dissecting/stereo microscope•2 eyepieces: binocular
•Magnifies 6-60 times
•shows external features (ex. fly, ladybug)
•creates a 3-D image
4. Electron-
SEM clip
•developed in 1930s
• bounces electrons off of specimen (instead of light)
•creates a 3-D image
•magnifies more than 250,000 times
• views specimens in a vacuum (kills live specimens)
Microscopic pictures from
http://news.nationalgeographic.com/news/2008/10/photogalleries/bestmicroscope-photos/photo3.html
Microscopic pictures from Nikon ppt linked here
Tips for microscope use:
•Start on low power
•Brighter
•Larger field of view
•To get total magnification: multiply the power of the eyepiece by
objective lens
•When you switch from low to high:
• center your specimen , b/c you will only see a
fraction of the center of the specimen when you go
to high power
•the field of view gets smaller and darker
•only use fine adjustment on high power
•objects appear upside down and backwards in the
field
under the
becomes
scope
•when you move the slide to the left, the image moves
to the right & vice-versa
Preparing a wet mount slide:
•add a drop of water to a slide
•add specimen (cheek cell, onion cell, etc.)
•put coverslip on at a 45o angle (removes air bubbles)
Staining a specimen:
•Place 1 drop of stain at the edge of the coverslip
•Place a paper towel at the opposite edge so that the
water from under the coverslip is absorbed and stain
is drawn under coverslip
specimen
paper
towel
stain
How do you measure organisms
under the microscope???
You can use a ruler under low power:
Cell scale
Microscopic Measurement:
Units: in a meter, there are 1000 mm (millimeters)
in 1 mm., there are 1000 um (micrometers/microns)
Determine the approximate
diameter of the cell in um.
The cell takes up approx
one quarter of the field
1.6 mm.
(diameter of the field of view)
1.6 / 4 = .4 mm.
= 400 um
Chromatography “chrom” = color
 process in which a substance (ink, chlorophyll) is
separated into its component parts/colors
 By comparing the separation color bands of the
unknown substances to a known substance
substance, an identification may be made.
Misc Lab Tips….
 Always wear goggles when using chemicals.
 When heating a material in a test tube:
 point tube away from you
 never put a stopper in the tube
 glassware:
beaker
test tube
Graduated cylinderflasks
always read volume
at meniscus
 Science uses the metric system:
grams
liters
meters
with prefixes such as
millicentikilo-
Conducting an Experiment:
A valid experiment must have the following elements:
 A question you are trying to answer or problem
you want to investigate
 A control- the setup that remains the same
through the experiment; provides a
comparison
 A variable- the element/factor that changes in
the experiment (amount of sun,
water)
-a valid experiment tests only ONE
variable at a time
independent- variable that does not depend on a
factor in the experiment (ex. time,
days)
dependent- relies on the independent variable
ex) plant growth depends on time, time
does not depend on plant growth
 A hypothesis- possible answer to the question
you are asking
often posed as an “if…then” statement
 An observation- what you see happening; provides
data for analysis
 Data- Information you collect, must be
measureable (height, length, number)
 A conclusion- Sums up the findings. Scientists
use the data to determine whether
the hypothesis was supported or
refuted
 Sample size- Refers to the # of organisms being
tested. The larger the sample size, the
more valid the results are.
 # of trials- the more trials you do, the more valid
your experiment is
The Cell
Cells overview





Smallest unit of living things
Present in all living things
Have many tiny “organs” called organelles
These organelles carry out life functions
Cells can be organized into more complex levels:
organelle
cells
tissue
organ
organ system
organism
 Cells are specialized to perform different functions
ex)nerve cells carry electrical messages
muscle cells move body parts
gland cells produce hormones
 Cells are most often microscopic (10- 100 um)
exceptions: chicken egg- 6 cm.
nerve cell- up to 1 meter!
WARNING!!!!!!!!!!!!!!!! Next slide is
graphic. It’ a picture of a real nerve in
someone’s arm during surgery.
Don’t look if it’ll make you sick!!
Nerve Cell
Cell Organelles
 small structures inside cell
 suspended in cytoplasm (the watery material
inside the cell where chemical reactions occur)
 carry out life functions
1. Cell (plasma) membrane-
Membrane function
clip
 Surrounds and protects the cell
 is selectively permeable (regulates the passage of
materials into and out of the cell) and therefore
maintains homeostasis (tries to)
*Life function: Transport, Regulation, Excretion
 Recognizes chemical signals from outside the
membrane or from other cells using:
receptors- structures on the membrane that
receive outside “messages”
(have specific shapes and will only
allow things inside the cell that
fit their shape!)
receptors
“message”
cell
Video clip:
membrane
Receptors:
Virus receptor clip,
http://phschool.com
use code cbp 6192
2. nucleus- control center for the cell
 contains:
chromosomes-(DNA in rod-like, coiled form
has instructions for entire
organism)
*Life function: regulation, reproduction, metabolism, etc
3. ribosomes synthesize proteins
 may be free in cytoplasm or lining E.R.
*Life function: synthesis
4. Endoplasmic Reticulum- (“ER”)
 a network of fluid filled channels connected to
the nuclear membrane
 transport materials w/in cell
 smooth ER- not lined w/
ribosomes
 rough ER- lined w/ribosomes
*Life function: transport, synthesis
Cell video Bill Nye
5. lysosomes-“stomach” of the cell
 small sacs that contain digestive chemicals
*Life function: nutrition
6. vacuole membrane enclosed sacs
~food: contain food & fuse w/lysosome
~ contractile: in freshwater protists, pumps out
excess water
 plant vacuoles are much larger than animal
*Life function: nutrition, excretion, homeostasis
7. mitochondria- (powerhouse)
 site of cellular respiration; releases energy (ATP)
*Life function: respiration
8. chloroplasts- found in plant cells only
contain chlorophyll
• site of photosynthesis
*Life function: synthesis, nutrition
12. Cell wall non-living
 surrounds & supports plant cells
 composed of cellulose (complex carbohydrate)
13. Cilia & flagella hair-like structures that help an organism move
cilia
flagella
*reminder………
 A cell can be part of a multicellular organisn (dog,
tree)
OR
 A cell can be an entire organism (ameba,
paramecium)
HOW?!
• the organelles present in a single celled
organism act like the systems (resp.,
excretory, etc) in a multicellular organism
• these organelles perform all of the life
functions needed to stay alive
*reminder………
plant cells
Large vacuoles
Chloroplasts
Cell membrane & cell wall
“cyto” = prefix meaning cell
Laser clip: cell
*review life funct
animal cells
Small vacuoles
No chloroplasts
Cell membrane only
jeopardy