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Final Review
Characteristics of Life!!!!!!
Cells, reproduction, adaptations,
DNA, responds to a stimulus, maintains,
homeostasis, growth and development,
and energy
Bacteria ReproductionVideo
Cells
• Basic building block of life!
ALL LIVING THINGS ARE MADE
OF CELLS or ORGANIZED CELLS
UNICELLULAR(single)
Unicellular organisms makeup
most of all organisms on Earths.
MULITCELLULAR
Many cells
They have everything they need to be self-sufficient.
Eukaryotic vs. Prokaryotic
• Eukaryotic – Contains a nuclear
membrane around their DNA. All
kingdoms except archaebacteria
and eubacteria!!!!
• Prokaryotic – No nuclear membrane –
all bacteria
Prokaryotic Cell
Eukaryotic Cell
Unicellular – one celled
Multi-cellular
In multi-cellular organisms, the cells
specialize to perform specific functions(bone
cells, skin cells, muscle cells, root cells, leaf
cells).
Smooth muscle
Nerve cell
Leaf cell
Yeast cell
Red Blood Cell
ALL LIVING THINGS MAKE
AND USE ENERGY
The SUN is the main source of energy!!!
The Sun makes light that is used by plants!!!!!!
What is the name of this process?
Plants(producers) trap the energy of the
Sun and make glucose(sugar) in the
process called photosynthesis).
Consumers(animals) get their energy from the
plants!!!!
Autotrophs(producers) – use the
Sun’s energy to make glucose!!
Produce their own food!
Photosynthesis – process where
plants convert Sun’s energy and carbon
dioxide into glucose
Heterotrophs(consumers) – must
consumer food for energy!
Homeostasis
• Process where organisms maintain a
stable internal balance.
Homeostasis
• Your body maintains a constant
internal and external physical
and chemical conditions.
Everything is happy!!
Goldilocks – Just Right!!!
Homeostasis
Dogs pant, you run a fever, sweat, or shiver,
cell membranes control amount of water
and waste in and out of cell, ETC
ALL LIVING THINGS
RESPOND TO A STIMULI
Living things respond to immediate and
long-term changes in their
environment(shiver when cold, change fur
color, bend toward light).
Stimulus – something in
organism’s environment that
causes a response
ALL LIVING THINGS
REPRODUCE
Reproduction must occur for a species to survive.
Reproduction can be either sexual or asexual.
Asexual Reproduction – NO joining
of sperm and egg!!!!
Sexual reproduction – combination
of sperm and egg
ALL LIVING THINGS
GROW AND DEVELOP
To grow means to get bigger and to get
bigger; more cells must be added.
To increase numbers of cells, cell
division must occur.
Develop means to change into an
adult(mature).
•
Living creatures GROW &
DEVELOP
Change over an individual’s life time
– get bigger
– mature
• so they can reproduce
Growth – Organism get larger by
adding cells and cellular material
Development - mature
ALL LIVING THINGS CHANGE
TO FIT THEIR
ENVIRONMENT(ADAPT)
Organisms must adapt to their changing
environment or become extinct.
Adaptations occur over a very long period
of time(millions of years).
Adaptation – Inherited trait that is
passed from parent to offspring that
helps an organism survive in its
environment
ALL LIVING THINGS
HAVE DNA.
DNA provides instructions for making
molecules called proteins. Proteins build
cells.
DNA carries the genetic material from
parent to offspring(heredity).
DNA – molecule that stores
genetic information
LET”S PRACTICE!!!
Which characteristics of life is being described?
Reproduction
Cells
Adaptation
Grow and develop
Responses
Energy
ENZYMES
A protein that acts as a catalyst
which lowers activation energy
needed to start a reaction.
*
*They speed up reactions by
weakening bonds.
*Always in in -ase
© 2007 Paul Billiet ODWS
How do enzymes Work?
Enzymes work
by weakening
bonds which
lowers
activation
energy.
Easier to start
reaction!!!
34
Enzymes
• Are specific
for what they
will catalyze
• Are Reusable
• End in –ase
-Sucrase
-Lactase
-Maltase
35
Enzymes have five important properties:
1.They are always proteins.
2. They are specific in their action. Each enzyme
controls one particular reaction, or type of reaction. Thus
sucrase degrades sucrose and only sucrose (table
sugar). ONE SUBSTRATE!!!
3. They are not altered by the reaction. This means
that an enzyme can be used repeatedly. It also means
that enzymes appear neither in the reactants nor in the
products of a chemical equation.
4. They are destroyed by heat. This is because
enzymes are proteins, and all proteins are destroyed by
heat. Destruction of protein by heat (or under any
extreme conditions of pH or salt concentration) is called
denaturation.
5. They are sensitive to pH.
The substrate
• The substrate of an enzyme are the
reactants that are acted on by the enzyme.
• Enzymes are specific to their substrates
• The specificity is determined by the active
site
• ENZYMES ARE SHAPED TO FIT ONLY
THEIR SUBTRATE BECAUSE THEIR
ACTIVE SITE IS SHAPED TO FIT ONLY
ONE SUBSTRATE!!!!
© 2007 Paul Billiet ODWS
The active site
PLACE WHERE
SUBSTRATE
FITS!!
ONLY THE ONE
SUBTRATE
WILL FIT!!!
© H.PELLETIER, M.R.SAWAYA
ProNuC Database
© 2007 Paul Billiet ODWS
Active Site
• A restricted region of an
enzyme molecule which
Active
binds to the
substrate.
Site
Substrate
Enzyme
39
Enzyme-Substrate Complex
This is the product of
the substrate and the
enzyme together.
Substrate
Joins
Enzyme
40
The Lock and Key Hypothesis
• Fit between the substrate and the active
site of the enzyme is exact
• Like a key fits into a lock very precisely
• The key is analogous to the enzyme
and the substrate analogous to the lock.
• Temporary structure called the enzymesubstrate complex formed
© 2007 Paul Billiet ODWS
Enzyme Structure
It fits like a lock and key with its
substrate. Will not fit any other
substance.
How Enzymes Work:
1. Enzyme brings molecules close
together.
2. By bonding they have weaken the
bonds of the substrate so they
reaction can occur quicker.
Induced Fit
• A change in
the shape of
an enzyme’s
active site
• Induced by
the
substrate
43
What Affects Enzyme
Activity?
• Three factors:
1.Temperature
2. pH
3.Inhibitors
44
Denaturing Enzymes
• Denaturing =- factors that change
the shape.
• Without the correct shape
enzymes won’t function properly.
• HOW are enzymes denatured?
– Temperature
*pH
Life Sciences-HHMI Outreach. Copyright 2009 President and Fellows of Harvard College
(–)
(–)
O
H
(+)
H
(+)
What Make Water Unique?
• Polarity and hydrogen bonds!!
Polarity of Water
In a water molecule two hydrogen atoms form single
polar covalent bonds with an oxygen atom.
– Oxygen is larger so the electrons stay around the
oxygen and not the hydrogen.
– This makes water charged.
– Oxygen area negative.
– The region near the two hydrogen
atoms has a partial positive charge.
A water molecule is a polar molecule
with opposite ends of the
molecule with opposite charges.
Water Molecule
• Water has a variety of unusual properties
because of attractions between these
polar molecules.
– The slightly negative regions of one molecule
are attracted to the slightly positive regions of
nearby molecules, forming a hydrogen bond.
– Each water molecule
can form hydrogen
bonds with up to
four neighbors.
Fig. 3.1
Copyright © 2002 Pearson Education, Inc., publishing as Benjamin Cummings
Hydrogen bond
Hydrogen Bonds Between DNA!!
WATER’S LIFE-SUPPORTING
PROPERTIES
Copyright © 2009 Pearson Education, Inc.
Water’s Properties
1. Cohesion & Adhesion
2. High Specific Heat
3. High Heat of Vaporization
4. Solid water (ice) is less dense than
liquid
5. Solvent
6. Transparent
1. Cohesion
• Water clings to polar
molecules through
hydrogen bonding
– Cohesion refers to
attraction to other water
molecules.
• responsible for surface
tension
– Surface tension - a
measure of the force
necessary to stretch or break
the surface of a liquid
– Some animals can stand,
walk, or run on water
without breaking the
surface.
Adhesion
• Adhesion: attraction between particles
that are different.
Examples: Blood to vessels, water to
xylem in plant. Clinging of one substance
to another.
Organisms Depend on Cohesion
• Adhesion is responsible for
the transport of the water
through the xylem in plants
against gravity.
• Capillary Action –
combination of adhesion
and cohesion that moves
water up the xylem.
• Water molecules stick to
walls of vessels and water
sticks to each other.
• Caused by Hydrogen bonds
Capillary action
water evaporates from
leaves = transpiration
adhesion,
cohesion and
capillary action
water taken up by
roots
Specific Heat
Specific Heat is the amount of energy
required to change the temperature of a
substance.
Water has a high specific heat – it absorbs
a lot of energy before it begins to heat up!
Takes a lot of heat to break apart the bonds.
HOW WOULD THIS HELP ORGANISMS!!
3. High Heat of Vaporization
**Because it also involves the breaking of
hydrogen bonds, water resists vaporizing
(evaporating).
Consequently, it takes a lot of heat to
evaporate water. This high heat of
vaporization is also utilized by organisms
as a cooling process, e.g., sweat or
panting.
3. EVAPORATIVE COOLING
• As a liquid evaporates, the surface of
the liquid that remains behind cools Evaporative cooling.
• Evaporative cooling moderates
temperature in lakes and ponds and
prevents terrestrial organisms from
overheating.
• Evaporation of water from the leaves
of plants or the skin of animals
removes excess heat.
4. Ice Floats
• When water freezes, hydrogen bonds lock
water molecules into a crystalline pattern
with empty spaces. This makes ice less
dense than water. So ice floats.
• Organisms can live below the ice!!!!
Solid water (ice) is less dense than
liquid
• Ice is less dense than water: the molecules are
spread out to their maximum distance
Density = mass/volume
same mass
but a larger
volume
5. Water is Transparent
• The fact that water is clear allows light
to pass through it. NOT BECAUSE OF H
BONDS!!
– Aquatic plants can receive sunlight
– Light can pass through the eyeball to
receptor cells in the back
6. Water Solubility
• Water Universal Solvent – Dissolves
other polar molecules!!!
• Solubility: the ability to be
dissolved. What would cause this?
• Charged ends of molecules attract
each other making them dissolve.
6. Solvent for Life
Hydrophilic
– Ionic compounds
dissolve in water
– Polar molecules
(generally) are water
soluble
• Hydrophobic
– Nonpolar
compounds
Autosomal vs. Sex
Chromosomes
INCOMPLETE DOMINANCE
Sometimes, you may notice that traits can blend
Together. The blending of two traits is call
incomplete dominance. Two capital letters are
used.
Examples – palomino in horses, pink color in
flowers are red and white combined.
What is meant by
MULTIPLE ALLELES?
• A trait that is controlled by more
than two alleles is said to be
controlled by multiple alleles
• Traits controlled by multiple alleles
produce more than three phenotypes
of that trait.
• Codominance – 2 alleles of a gene are
completely expressed and both
phenotypes are completely expressed!
• BOTH COLORS OR PHENOTYPES ARE
EXPRESSED!!!
• Black and white cow!
Codominance
• Both alleles are expressed
1.
type A= IAIA or IAi
2. type B= IBIB or IBi
3. type AB= IAIB
4. type O= ii
Where are Disorders Located?
• Autosomal chromosomes: 1 - 22
– The disorder is caused by a gene or
nondisjunction of chromosomes 1 - 22.
* Sex Linked disorders: Located on the X
or Y chromosomes.
Sex Linked Genes
Sex Linked Traits or Disorders - The X
and Y chromosomes carry the genes
that determine gender traits so the
genes located on X and Y are called
sex linked.
• X – 1098 genes
• Y – 26 genes much smaller!!!
Sex Linked Genes
• The genes that are on the X are
expressed in the phenotype of the male
because it is the only gene they carry. If
the gene is a recessive for a disorder,
the male will have the disorder.
• Ex: hemophilia, duchene muscular,
fragile-X syndrome, high blood
pressure(some), night blindness, and
red-green color blindnesss.
Sex-Linked Inheritance
• Traits that are only found on the X
chromosome
• Colorblindness and Hemophilia are
examples of sex-linked traits.
• These genes are recessive and found only
on the X chromosome.
How Would a Female Have a
Sex Linked Disorder?
• She would have to receive a recessive
gene from both parents.
Goals of Pedigree Analysis
1. Determine the mode of
inheritance: dominant or
recessive, autosomal or sexlinked, .
2. Determine the probability of an
affected offspring for a given
cross.
Today... Pedigree analysis
4 Types of Basic patterns or modes of
inheritance
autosomal, recessive
autosomal, dominant
X-linked, recessive
X-linked, dominant (very rare)
Sample pedigree - cystic fibrosis
male
female
affected individuals
Dominant Autosomal Pedigree
I
2
1
II
1
2
3
4
5
6
III
1
2
3
4
5
6
7
8
9
10
Autosomal Recessive
• All affected are
homozygotes.
• Unaffected outsiders
are assumed to be
homozygous normal
Autosomal recessive traits
• Trait is rare in
pedigree
• Trait often skips
generations (hidden
in heterozygous
carriers)
• Trait affects males
and females equally
Recessive Autosomal Pedigree
Autosomal recessive diseases in humans
Most common ones
•Cystic fibrosis
•Sickle cell anemia
•Phenylketonuria (PKU)
•Tay-Sachs disease
Sex-Linked Recessive
• males get their X from their
mother
• fathers pass their X to
daughters only
• females express it only if
they get a copy from both
parents.
• expressed in males if
present
• recessive in females
• outsiders are assumed to be
homozygous.
X-linked recessive pedigrees
• Trait is rare in pedigree
• Trait skips generations
• Affected fathers DO
NOT pass to their sons,
• Males are more often
affected than females
X-linked recessive traits
ex. Hemophilia in European royalty
•
•
•
•
Three types of RNA:
1. mRNA
• 2. tRNA
“messenger” RNA
• “transfer” RNA
Carries code for
• Attaches specific
proteins from DNA
Amino Acids to the
Carries “codon”
protein chain by
matching the mRNA
codon with the
anticodon.
RNA TRANSCIPTION
There are three (3) types RNA:
1. Ribsome RNA – (rRNA) makes up the
ribsome. Site of protein synthesis
Structure of the Cell Membrane
Outside of cell
Proteins
Lipid
Bilayer
Transport
Protein
Animations
of membrane
Go to structure
Section:
Carbohydrate
chains
Phospholipids
Inside of cell
(cytoplasm)
How does stuff get in and out of the
cell?
• The cell membrane is what allows stuff in
and out of the cell. The membrane is
selectively permeable.
• Selectively permeable• Definition- means that some substances
can cross the membrane while others
cannot.
Polar heads
love water
& dissolve.
Non-polar
tails hide
from water.
Carbohydrate cell
markers
Proteins
Fluid Mosaic
Model
This model
describes the
structure of the
cell membrane!!
How do phosolipids control what can pass
through Membrane?
The hydrophobic tails will not let any substance
pass through that has a charge(ion)(hydrophilic).
Only substances that are not charged
(hydrophobic)can pass through. If they cannot
pass through the membrane, then they must go
through the must get in another way.
Cell Transport
•
•
•
•
•
•
To understand cell transport, you must
understand how molecules move.
All molecules move. Even solids vibrate.
Most of the cell environment is liquid.
Molecules want to reach EQUILIBRIUM!
Equilibrium – equal amount of molecules
everywhere(across cell membrane).
Types of Active Transport
• Active – requires energy against the
gradient
• Passive – no energy required. Uses the
concentration gradient!
Diffusion
• Movement of molecules moving from an
area of higher concentration to an area of
lower concentration.
• Example: air freshener, perfume, food
cooking, food coloring in water.
• Increase temperature; increase rate of
diffusion
• Diffusion occurs in liquids and gases.
Which direction will molecules
flow?
Concentration Gradient
• Difference in concentration of molecules
that makes the molecules move. They
move from highest level to the lowest
level.
• The greater the difference the faster the
molecules move.
Diffusion video
• http://video.search.yahoo.com/search/vide
o;_ylt=A0SO8ZpVTNdMKS8AS3H7w8QF;
_ylu=X3oDMTBncGdyMzQ0BHNlYwNzZ
WFyY2gEdnRpZAM-?p=diffusion&ei=utf8&fr2=tab-img&n=21&tnr=21&y=Search
How does stuff get in and out of the
cell?
• Substances that move into and out of a
cell do so by means of one of two
processes: PASSIVE TRANSPORT or
ACTIVE TRANSPORT.
Types of Cell Transport
• No Energy
• Passive Transport
Energy
Active Transport
– Diffusion
Faciliated diffusion(osmosis)
Bulk transport
endocyotsis
exocytosis
Passive Transport
• http://video.search.yahoo.com/search/vide
o;_ylt=A0PDoX1LTNdMKyoAZayJzbkF?ei
=UTF-8&p=passive%20transport&fr2=tabimg&fr=The Cell and Its Environment
2010.ppt
Passive Transport
• Definition: is the movement of dissolved
materials across a cell membrane without
using the cells energy.
• Energy required: NO
• Type of Transport: PASSIVE
• Diffusion or facilitated diffusion(osmosis)
Passive Transport
Diffusion – passive transport
• Definition: is the process by which molecules
move from an area of higher concentration to an
area of lower concentration(liquids or gases).
• Ex: If a bacteria lives in a pond, the water in the
pond contains oxygen molecules. The area
inside the bacteria cell has a lower amount of
oxygen than the pond. So, the oxygen
molecules outside of the cell will freely move into
the cell.
Faciliated Diffusion- Type of
Passive Transport
• Movement of molecules across the cell
membrane but using a carrier
molecule(protein)
• NO ENERGY
• Follows the same rules as diffusion but
these molecules cannot slip through the
phosolipid tails.
Osmosis – facilitated diffusion
• Definition: is the diffusion of water
molecules across a selectively permeable
membrane(sometimes uses carrier
protein).
• -Many life processes require water,
therefore; all cells must have the
appropriate amount of water in them to
function.
• Energy Required: NO
• Type of Transfer: PASSIVE
Osmosis – Type of Faciliated
Diffusion
• Movement of WATER across the cell
membrane.
• Cells are 75 – 90 % water so osmosis is
• an important process.
• Water molecules will continue to move
until EQUILIBRUIM is reached.
• NO ENERGY NEEDED!!
Types of solutions cell can be
placed
• Isotonic
• Hypertonic
• Hypotonic
Isotonic
• Concentration of solutes are EQUAL
inside and outside the cell.
• Why do they give a person who is
dehydrated a saline(minerals and salt)
drip(IV) vs. distilled 100% water.
Hypertonic
• Solutes on the outside of cell is higher.
Water leaves cell
• This is why slugs shrivels up with salt.
• Animals that leave in salt water have
adaptations to deal with the salt in the
water.
• This is why you do not drink salt water.
• How will road salt affect roadside plants?
Hypertonic Solution
Cells are
shrinking
because more
solute outside
so water
leaves cell.
Hypotonic
• Concentration of solute is greater inside
the cell so water moves in.
• Animal cell will burst.
• Plant cells fill vacuole creates RIGOR!
• This is what causes plant to stand up.
Hypotonic Solution