2. 4.1 The Ingredients of Life
• A. The Building Blocks
• 1 Organic compounds – molecules containing
C, H, & O
• Make life possible
• High-energy molecules
Energy used to synthesize
Energy released in breakdown
• Four types of organic compounds
3. 2 Carbohydrates – sugars
• Glucose – metabolized for energy
• Starches – long chains of simple sugars used
for energy storage
• Chitin – skeletal material
• Cellulose – cell structure
4. 3 Proteins
• Chains of amino acids
• Muscles are mostly made up of proteins
• Enzymes – catalyze reactions
• Structural proteins – skin, hair, skeleton
• Hormones
5. 4 Lipids
• Fats, oils, & waxes
• Energy storage – more than twice as much as
sugar
• Water repellant
• Buoyancy
• Insulation
• Hormones
6. 5 Nucleic Acids
• Store and transmit the genetic information of
all living things
• Long chains of subunits called nucleotides
• DNA – instructions for the construction and
maintenance of an organism; the complete set
is called the genome
• The nitrogen bases are sequenced into genes
that code for a specific protein
• RNA – helps DNA
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11. B. The Fuel of Life
• ATP – the molecule used to store energy; like
a rechargeable battery
• You use ~ 125 lbs./day
• Organisms need to capture, store and use
energy
• Most organisms use only two sets of reactions
12. 1 Photosynthesis: Making the Fuel
• Algae, plants, and some microorganisms
• Capture the sun’s energy and use it to make
glucose
The pigment chlorophyll captures the solar
energy
CO2 + H2O → C6H12O6 (glucose) + O2
• We rely on photosynthesis for food and oxygen
• Organisms that photosynthesize are called
autotrophs
Plants on land; bacteria and algae in the ocean
13. 2 Respiration: Burning the Fuel
• Both autotrophs and heterotrophs do it
• Releases the energy from org. compounds
• Reverse of photosynthesis
Organic matter (glucose) + O2→ H2O + CO2
• Similar to burning wood or oil
• Chemical energy captured in ATP
• Aerobic – uses oxygen, more efficient
• Anaerobic – does not use oxygen, less
efficient
14. 3 Primary Production
• Most of the glucose is used for fuel or
converted into other types of org. compounds
• The organic matter autotrophs make is called
primary production
Used by the organism for growth and
reproduction
• Autotrophs are also called producers
15. 4 The Importance of Nutrients
• Vitamins, minerals and other substances are
needed to convert glucose into other org.
compounds
• Nitrogen for proteins & nucleic acids
• Phosphorus for nucleic acids
• Silica (SiO2) to make shells
• Iron – necessary, but a limited resource in the
ocean
16. 4.2 Living Machinery
• Organic compounds are organized into
functional units that are alive
17. A. Cells and Organelles
Cell – basic unit of life
All organisms are made of cells
Wrapped in a cell membrane
• Cell is filled with jelly-like cytoplasm
• Organelles have specific jobs in the cell
18. 1. Structurally Simple Cells: Prokaryotes
Prokaryotes are primitive cells
Ancient, simple, small
No membrane-bound organelles
Bacteria
Prokaryotes have few structures:
Cell wall – support
Ribosomes – assemble proteins
DNA – loose in the cytoplasm
Flagella – locomotion
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20. 2. Structurally Complex Cells: Eukaryotes
Eukaryotic cells are organized and complex
Larger than prokaryotes
Have specialized organelles:
Nucleus – contains chromosomes (DNA)
Endoplasmic reticulum – make proteins and other org.
molecules for the cell
Golgi apparatus – package and transport molecules
Mitochondria – respiration center to provide energy
Flagella and cilia – for movement
Only in plant & algal cells
Chloroplasts – photosynthesis center
Cell wall - support
21. B. Levels of Organization
1. A cell is self-contained and can carry out all the functions
necessary for life
• Unicellular – all prokaryotes and some eukaryotes
• Multicellular – most eukaryotes
Human body has 100,000,000,000,000 cells
• In multicellular organisms cells specialize to perform
different tasks for the organism
• Cells that act together for a specific job are called tissues
Muscle, nervous, bone, blood, epithelial
• Tissues are organized into organs to carry out specific
functions
Liver, kidney, heart, skin, brain
• Organs act together in an organ system
Skeletal, muscular, excretory, endocrine, digestive
22. 2. Organization exists outside the individual
organism
Species – one type of organism
Blue mussel
Population – a group of one species
A bunch of blue mussels
Community – several different populations that live
and interact in an area
Blue mussels, crabs, barnacles, & chitons living on a
rock
Ecosystem – the communities living together with the
physical environment
Living on a rocky shore with seawater, air,
temperature, sunlight, etc.
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24. 4.3 Challenges of Life in the Sea
• Marine organisms must cope with different
problems than on land
• They have evolved ways to adapt to their
marine habitat
• Most important is maintaining homeostasis
Keeping their internal condition normal
regardless of the external condition
25. A. Salinity
• Marine organisms are immersed in a medium
– sea water – that can greatly affect their cell
function
• Enzymes and organic molecules are sensitive
to ion concentration (salinity)
26. 1. Diffusion and Osmosis
• Dissolved ions move around in water
• Random movement spreads them out in an even
distribution
• Results in diffusion – movement from high low
concentration
• When concentrations are different inside and
outside a cell, substances will move in/out by
diffusion
Salt from seawater will diffuse into the cell
Nutrients will diffuse out of the cell
• The cell membrane blocks block diffusion
It’s selectively permeable – it allows only some
substances to go in/out
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28. • Water is a small molecule and can fit through the
cell membrane
It also diffuses from high → low concentration
If a cell has more solutes inside than outside,
water will stream in and swell the cell
If the seawater has more salt, water will leave
and the cell will shrivel
This diffusion of water is called osmosis
• Cells may need to move materials against
diffusion (low high)
e.g. expelling extra salt or taking in more sugar
Active transport – proteins in the cell membrane
pump materials using ATP
1/3 of the cell’s energy is spent on this
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30. 2. Regulation of Salt and Water Balance
• Marine organisms have adapted ways to balance water
and salt
• Osmoconformers –their internal concentrations
change with the salinity of the seawater
Live in a narrow range of salinity
• Osmoregulators – control internal concentrations to
avoid osmotic problems
Can tolerate changes in salinity better
Can change their internal concentrations to match the
seawater
Salt water fishes lose water by osmosis
Drink water or reduce urine amount to replace lost
water
Excrete excess salts in the urine or through the gills
31. Freshwater fishes gain water by osmosis
Don’t drink water or produce lots of urine
Salt absorbed by gills
Some marine birds and reptiles have special
glands to get rid of excess salt
Most algae have rigid cell walls that resist the
swelling caused by osmotic water gain
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33. B. Temperature
Metabolic reactions speed up/slow down
when temperature goes up/down
Metabolic rate doubles every 10oC
At extreme temps most enzymes cease to
function
Marine organisms are adapted to live in a
temp range
Thus determining what regions of the oceans
they live
34. Ectotherms – “cold blooded” lose their heat to the
seawater
Endotherms – “warm blooded” retain heat and keep
their body temp higher than the water
Mammals, birds, and some large fishes
Poikilotherms – body temp changes with the temp of
the seawater
Incl. all ectotherms & endothermic fishes
Homeotherms – keep internal temp the same,
regardless of outside temp
Produce more heat as need to keep their metabolic
activity high
Mammals & birds
They need to eat more food
Insulate their bodies with feathers, hair, and blubber
35. C. Surface-to-Volume Ratio
Heat and materials exchange across the
surface of an organism
The surface-to-volume ratio (S/V ratio)
determines how rapidly this happens
As organisms get larger the volume grows
faster than the surface area
Small organisms rely on diffusion
Large organisms respiratory and excretory
systems
36. 4.4 Perpetuating Life
A species must reproduce or vanish from the
planet
Produce a new offspring
Pass on the genetic information
37. A. Modes of Reproduction
Cells reproduce through cell division
Cell fission in prokaryotes; mitosis in
eukaryotes
Results in identical daughter cells
38. 1. Asexual Reproduction
No partner
Offspring are genetically identical – clones
Most single-celled organisms reproduce this way
Some multicellular organisms do:
Some sea anemones will split in half, making two
smaller ones
–fission
Some sponges develop growths that break off to
become separate individuals – budding or
vegetative reproduction
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40. 2. Sexual Reproduction
Union of two separate gametes from two parents
Ovaries – female gonads that produce eggs
Testes – male gonads that produce sperm
Meiosis divides the chromosomes in half; Fertilization
combines them to form a full
set again
A fertilized egg is called a zygote. It has DNA from both
parents
This genetic recombination causes variation in the
offspring
Greatest advantage of sexual reproduction
The zygote divides by mitosis and eventually forms an
embryo
May pass through a larval stage on the way to adulthood
41. B. Reproductive Strategies
The goal of reproduction is to pass on the genes
Varying reproductive strategies to get the same
result
Broadcast spawning – release millions of eggs
and sperm into the water
No parental care, most die
Have few offspring and invest more time and
energy into their survival
Some use sexual and asexual reproduction
Some species are hermaphroditic, both sexual
organs
42. 4.5 The Diversity of Life in the Sea
• The vast diversity of organisms in the ocean
came through millions of years of evolution
• The gradual alteration of a species’ genetic
makeup
43. A. Natural Selection and Adaptation
Individual organisms show variation in how they:
Find food, avoid being eaten, reproduce, find
mates, metabolize, etc.
The best-adapted produce more offspring than
the others
This process is called natural selection
As their genes get passed on the favorable traits
become more common
The population’s genetic makeup changes over
time as it adapts to its environment
Populations either adapt to the changes in the
environment or become extinct
44. B. Classifying Living Things
To discuss the huge variety of life forms we
must first classify them
1. The Biological Species Concept
What is a species? A type of organism?
A population with common characteristics
that can successfully breed with each other
(fertile offspring)
If two populations cannot interbreed they are
reproductively isolated
45. 2. Biological Nomenclature
• Organisms are identified with a two-word
name - Genus and species
• Blue whale – Balaenoptera musculus
• Fin whale – Balaenoptera physalus
• Minke whale – Balaenoptera acutorostrata
• Latin or Greek is used for naming
• Common names are confusing, scientific
names are used worldwide to precisely
identify a species
48. 3. Phylogenetics: Reconstructing Evolution
Organisms are grouped according to their
relatedness
Related organisms share an evolutionary
history, or phylogeny
They share a common ancestor
Look at fossil record, anatomy, reproduction,
embryological development, DNA, behavior,
etc.
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50. 4. The Tree of Life
• Classifications have changed over time
• Started with two kingdoms – Animalia and
Plantae
• Then five kingdoms – added Fungi, Monera, &
Protista
• Then three domain system