Transcript Life in the Sea - Mr. Sanchez, The Marine Biology Science Guy

Life in the Sea
Carbohydrate
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Elements: C, H, O
Function: nutrients for
cell/ energy
ex: sugar (simple)
starch (complex)
Carbohydrate
1
2
1
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3
2
5
12
4
5
6
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7
9
11
4
8
Carbo + hydrate
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3
10
Monomer:
monosaccharide (single
units of sugar C6H12O6)
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6
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Carbon + water (H2O)
2:1 Hydrogen: Oxygen
-ose (sugar)
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Glucose, fructose,
galactose, amylose
Carbohydrate
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Disaccharide: two
monomers put
together
ex: maltose,
lactose, sucrose
Carbohydrate
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Polysaccharides
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“many”
Thousands of
monomers linked
together
ex: starch (potato,
pasta, rice, etc.)
Carbohydrate: Polysaccharides
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Cellulose
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plant cell walls
Indigestible
Chitin
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exoskeletons (shells)
Also found in fungi cell
walls
Lipids
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Elements: C, H, O
Function: Energy
storage
ex: fat, wax,
steroids, cell
membranes
Lipids
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No monomers (no
repeating of single
units)
hydrophobic
Functional group:
carboxyl group
Lipids: Fats
 One
glycerol
 Fatty
acids
(carboxyl group +
hydrocarbon chain)
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Soap made from fatty
acids
Lipids: Saturated
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Carbon chain with
only single covalent
bond
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excludes double bond
in carboxyl group
Hard at room
temperature
Lipids: Unsaturated
 Carbon chains with
one (unsaturated) or
more
(polyunsaturated)
double bonds
 excludes double
bond in carboxyl
group
 “Kink”
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Soft at room
temperature
Lipids: Phospholipids
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Polar, hydrophilic
head
Non-polar
hydrophobic tails
Found in cell
membranes
Protein Characteristics/Functions
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Antibodies for defense
Enzymes for
catalyzing reactions
Made of 20 different
amino acids
movement
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Monomer: aminoProteins
acids
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Functional group:
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Carboxyl group
Amino group
Central carbon
“R” group (variable)
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Determines unique physical
and chemical characteristics
Protein Structure
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Effected by temperature
and pH
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Shape determines its
function
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Folds in proteins aided
by chaperone proteins
Nucleic Acids
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Elements:
C, H, O, N, P
Function: genetic
material/energy
molecule
ex: DNA, RNA, ATP
Monomer: Nucleotide
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Phosphate group
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Sugar:
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ex: Deoxyribose
Nitrogen Base:
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examples:
 Adenine
 Thymine
 Cytosine
 Guanine
The Need for Classification
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Three reasons for classifying
organisms:
 1. It helps identify the
relationships between
organisms.
 2. It requires scientists to clearly
identify
key characteristics of each
organism.
 3. It avoids confusion. Common
names differ
with cultures. Scientists
in the US and Japan can
identify exactly what
they are both talking
about by using the
species’ Latin name.
 Latin is a dead language
Classification Taxa
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An organism’s scientific name represents two
taxa. They are:
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1. Species – is the most specific of the taxa. Species
is usually considered to be a group of organisms that
can reproduce together.
2. Genus – is the taxon above species. Genus
grouped species are considered to be closely related,
i.e., there are 34 species of reef shark belonging to
genus Carcharhinus.
Species are identified by referring to both the
genus and the species, with the genus
capitalized and the species name in lower case.
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There are seven main taxa into
which organisms are classified;
from the general to specific:
1.
2.
3.
4.
5.
6.
7.
Kingdoms are groups of phyla
(plural of phylum).
Phylum (or division) is a group
of classes.
Classes are groups of related
orders.
Orders are groups of related
families.
Families are groups of genera
that share characteristics.
Genus (plural genera) groups
species that are closely related.
Species is the Latin name for an
individual organism.
Determining Taxa
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How organisms are
classified:
 Originally by using
anatomical features.
 The prevailing view now is
that taxonomy generally
reflects theoretical
evolutionary relationships.
 Classifying by
anatomical features
remains an important
classification method.
However, the study of
genetics has become
more important.
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A common problem taxonomists have in
classifying organisms is that some organisms
don’t fit neatly into defined classifications.
An organism can have characteristics that fit in
one and others that separate it from that same
classification.
The answer is to insert intermediate
classification levels.
 By assigning superlevels to create new
higher divisions within a classification.
 By assigning sublevels to create lower
divisions within a classification.
Six - Kingdom System and
Three - Domain System
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Until recently taxonomists
recognized five kingdoms:
kingdom Monera, kingdom
Protista, kingdom Fungi,
kingdom Plantae, and
kingdom Animalia.
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The six-kingdom system
divides kingdom Monera into
two new kingdoms: kingdom
Eubacteria and kingdom
Archaebacteria.
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The three-domain
system method is
based on genetic and
biochemical research.
 Domain Archaea is
composed of
organisms scientists
think evolved first.
 In this system
domain Eukarya
includes the
Protista, Plantae,
Fungi and Animalia
kingdoms.
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Old and Simple
Prokaryotes are among the most
important
of the primary producers in the ocean.
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They don’t have the same complex internal
membrane structure.
They lack chromosomes or a nucleus.
Instead
they have a ring of DNA or RNA.
They don’t have mitochondria and
lack chloroplasts.
They are structurally simple – molecules
are surrounded by a membrane and cell
wall.
They are believed to be the oldest types of
organisms – archaea originated
3.5 billion years ago.
Scientists think that the process of
photosynthesis began with cyanophytes
of domain Bacteria, an early prokaryote.
Archaea and Bacteria
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Domain Archaea and domain Bacteria are best known for
being
extremophiles – living in environments that are inhospitable
to most life.
Bacteria can do things no other known organisms can do:
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The most important bacteria are in the phylum Cyanophyta.
Scientists think that these bacteria are crucial to life because:
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Certain species can create organic nitrogen compounds by fixing
inorganic nitrogen from the air – an essential element of life.
Photosynthesis evolved in the cyanophytes.
Cyanophytes were the primary organisms that created the
oxygen in the atmosphere.
Cyanophytes are among the bacteria responsible for nitrogen fixation.
Also, some scientists think we presently underestimate the
role cyanophytes play in primary productivity. Their
pigments can contribute to the color of other organisms.
A Broadly Applied Name
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Algae is defined by taxonomists as those
organisms that belong in one of seven
specific phyla or divisions in kingdom
Protista.
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1.
2.
3.
4.
5.
6.
7.
Chlorophyta
Rhodophyta
Phaeophyta
Dinophyta
Bacillariophyta
Euglenophyta
Chrysophyta
Phylum Bacillariophyta – The
Diatoms
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Phylum Bacillariophyta is made up of diatoms, the most productive
phytoplankton.
These primary producers are a widely
diverse group.
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Between 5,000 to 50,000 species may
make up this phylum.
Diatoms are larger than prokaryotes
– from 20 to 80 microns across.
They have two-part silicon shells in
an amazing array of shapes.
They are photosynthesizers that are
relatively dormant during the winter
months.
Diatoms reproduce quickly when
sunlight levels rise and are thought
to account for 25% of all the photosynthetic biomass on Earth.
Phylum Dinophyta – The
Dinoflagellates
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Dinoflagellates make up phylum Dinophyta (also called phylum
Pyrrophyta or phylum Dinoflagellata).
In size they are 30 to 150 microns across and
are the second most productive group of
primary producers.
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Symbiodinium are particularly important
autotrophic dinoflagellates.
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They live within the zooxanthellate
coral polyps.
They provide their host with food via
photosynthesis.
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In return Symbiodinium get nitrogenous
wastes from the coral.
These are the only coral that build massive coral reefs.
Without Symbiodinium, coral could not exist as we know it.
Without coral and coral reefs there would not be the unique organisms
that make up the world’s most productive and beautiful ecosystems.
Phylum Chlorophyta – Green
Algae
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Phylum Chlorophyta is made up of the macro
algae – a term that applies to several algae phyla,
but refers to multicellular species like seaweed.
They share the same green color as land plants.
Both green algae and land plants have:
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Chlorophyll a – a pigment directly involved
with photosynthesis.
Chlorophyll b – assists chlorophyll a in capturing light
for use in photosynthesis.
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Chlorophyll a and b absorb different colors of light, thus using light more
efficiently.
Scientists think the presence of chlorophyll a and b has evolutionary
significance. It may indicate that land plants evolved from green algae.
Green algae and land plants also have other pigments in common and
have cell walls made of cellulose.
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Phylum Rhodophyta – Red
Algae
Red algae is red because they have pigments called
phycoerythrins
which give it their color.
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Phycoerythrins allow some red algae
to live deeper than any other algae –
some as deep as 200 meters (656 feet).
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This pigment has not been found in any other eukaryote, though
it does exist in cyanophytes.
Red algae also has chlorophyll a, but not b.
Red algae is important to coral reefs
because it is the cement that holds
the coral reefs together.
Red algae species that live on coral reefs
secrete a calcium carbonate shell.
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Their secretions bond coral colonies and debris
together which in turn holds the reef together.
Phylum Phaeophyta – Brown
Algae
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Phylum Phaeophyta (brown algae), is more
structurally complex. Many
brown algae species have:
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Holdfasts – anchor the algae to the bottom.
Leathery stipes – provide support like plant
stems, but with no vascular system.
Blades – equivalent of leaves.
Pneumatocysts – gas filled float structures
that lift the algae off the bottom and keep the
blades close to the surface and sun.
Kelp is the largest of the brown algae.
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Kelp is important because it is the foundation for
many temperate coastal ecosystems.
Bioluminescence
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light that is biologically produced and is
caused when a light-emitting molecule, called
luciferin, is mixed with an enzyme, luciferase,
in the presence of
oxygen.
Bioluminescence is actually quite common
and almost all taxonomic groups of animals,
and many plants, have some members that
bioluminesce.
Planktonic dinoflagellates and bacteria are
some of the most abundant creators of this
biological light
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Reasons for bioluminescence vary
depending on the organism
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escaping predators
obtaining prey
Attraction
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