Biology Unit 1 Notes
1t CellTheory
Livingorganisms are composed of cells
cells are the fundamental building blocks of all
living
organisms
The smallest organisms are unicellular
They consist of one cell
Largerorganisms are multicellular
They are composed cells
of many
common Features
cell is surrounded a membrane
every living
which separates the by
cell contents from everythingelse
from outside
cells contain material which stores all
genetic
instructions needed for the cell's activities of th
manyof these activities arechemical reactions catalyzed
byenzymes produced inside the cell
cells have their own releasesystem that powers
cell's energy
all of the activities
cell theory
Cells are the smallest unit
1
2 All livingthings are composed cell of life
3 Cells of
arise from pre existing cells
only
magnification arealSIZE
cell theory's exceptions
Striated Muscle
they are muchlarger than most animal cells
Aseptate HyphaFungi
some fungi are
fungi cosist
of narrow thread like structures called
not partitioned hyphae
s hence in some the hyphae are divided into small
y septa
are a continous cell types
walls of fungi
called
septa
cytoplasmalong each
hypha uninterrupted tube like structure
is an
the lengthof the with nuclei spread along it
hyphae
many
Challenges the idea that livingstructures're composed
of discrete cells
Giant Algae
Subdivision into organisms that feedtientfies
are glees
giant algae
eperate cells photosynthesis and store their genes inside nuclei butthey
are simpler in their structure and organizationthan plants
that to much
cells larger
some
algae
still seem to grew a size yet
they
Acetabularia
be
single
Unicellular Organisms celltcotries out all
Organisms consisting of only one
in that cell
functions of life
chenticatterside me
ÉÉÉÉÉ
energy gang
to provide
g
and the cell including cell respiration
to releaseenergy
organisms must obtainfood
to provide energyfor
metabolism
ÉÉÉtyTo react to
Irons
of an irreversible'Initese i
changes in theenvironment get size
abilityto react to stimuli
guqin size
ÉÉi Ée th Tasteproducts keepingtondffntitiethe
withintolerable limits
organism
hernconditions
IqmgI
Producing Offsprings either sexually
on
Paramecia
are unicellular organisms that are found infreshwad
or other marine environments
Reproduction
the nucleus the cell can divide to produce
of
the extra nuclei that are needed when cell
reproduces Often it reproduces asexually
Nutrition
the Food Vacuoles contain smaller organisms that
the Paramecium has consumed
are digested and the nutrients an
They gradually
absorbed into the cytoplasm where
s materials needed for growth they
provid
energy
Excretion
the cell membrane Paramecium controls what
of
chemicals enter s leave
Excretion happens simply for
respiration
It ggistheniggetta by wasteproducts diffusing
Movement Response
the cilia moves the Paramicium through
Beating of
the H2o and this can be controlled the cell so
that it moves in a particular by
direction in response to
changes in the environment
Metabolism
Metabolic reactions take place in the cytoplasm
the reactions that release energy
including
respiration by
Enzymes in the cytoplasm are the catalysts that
cause these reactions to happen
contractile vacuoles at each end of the cell fi
up with water and then expel it through the plasma
for paramecia membraneiii of the
cell to keep the cell s water
content within tolerable limits
www mn
Reproduction
Jiff the nucleus of the cell divide to producegenetically
identical nuclei asexual reproduction
here
exam as
is
for
well Nuclei can also
fuse s divide to out
sexual reproduction carry
Nucleus can be coveredhey chloroplasts
Metabolism
metabolic reactions take the
with enzymes present to place inthem cytoplasm
speed up
Excretion
the cell wall is permeable s it is
if Fullycell
permeable the membrane freely
inside it that controls what
chemicals enter s leave
is a waste product
Oxygen
and is excreted of
out
photosynthesis
the
membrane by diffusing through
SAN ratio
Decrease of limitation
cell size
exponentially the metabolic rate a cell is proportional to thevolume
the cell of
Cell divide
of
For metabolism to continue substances used inthe
that theycan reactions must be absorbed and waste products
maintain thesame must be removed the plasma membrane
dume but the rate through
at which substances cross this membrane
drasticallyincreasedepends on its surface area
A
Eh If
will
SA V is too
ratio small then substances
not enter the cell as
quickly as
they ar
heat produced required and waste products will accumulate
because
due than they are produced
can be excreted
more
rapidly
they
metabolism I
waste product Ifbecause
SA v ratio is too small it overheat
accumulation the metabolism produces may
heat faster
than it is lost over the cell's surface
larger cells need more
for movement metabolism
energy
SA equates to more material
longer
I Volume increases faster than the SA b
I examples I pageffinious
eaters
Vili
ruffled c
Intestinal tissue ofthe within the lungs
structure
that increase digestive tract may form a have membraneous extensions
SA ruffled structure vili to called microvilli
theinner
to ing
increase sit
of lining Function to increasethe total ment
surface
Emergent
Interaction
Properties
individual
of component produce newfunction
Multicellular organisms are capable
functions that unicellular organisms
of
could
completing
not undertake
this is due to the collective actions indie
of
cells combining create new synergisticeffects
to
cells be grouped together to form tissues
Organsmay
are then formed
from thefunctionalgrouping
of multiple tissues
organs thatoutinteract mayformorgansystems capable
of carrying specific body
out
function
the
Organ systems carry
complete organism
life function of the
cell Tissue Organ often Organism
Mae Cardiac Tissue
Heart
Haggler Human
