Transcript The Necessities of Life

The Necessities of Life
WATER
Cells = 70% water
Chemical reactions in
metabolism require water
Humans can only survive
about 3 days without
Water comes from fluids and
food
AIR
Air includes oxygen and carbon dioxide
Oxygen is used in chemical process to
release energy from food (cellular
respiration)
Green plants and algae need carbon
dioxide to produce food (photosynthesis)
Anaerobic organisms – will not grow in the
presence of air (Clostridium botulinum –
bacteria that make humans sick)
PLACE TO LIVE
Need place that contains
all of the things needed to
survive
Organisms often compete
for space
FOOD
Energy
Replace cells
Build body parts
Organisms are grouped
based on how they obtain
food
PRODUCERS
Plants and algae
Energy from sun
Water + carbon dioxide
PHOTOSYNTHESIS
Releases glucose (sugar)
+ oxygen gas
CONSUMERS
Must
consume other
organisms for
food
NUTRIENTS
Made of molecules
Molecules = 2 or more atoms
Compounds = 2 or more different kinds of
atoms
Living things compounds include 6
elements: carbon, hydrogen, nitrogen,
oxygen, phosphorus, and sulfur
These elements form proteins,
carbohydrates, lipids, ATP, and nucleic
acids
PROTEINS
Made up of smaller molecules called amino acids
Protein in food is broken down to supply cells
with amino acids
Some proteins = a few amino acids
Some proteins = 10,000 amino acids
Red blood cells contain protein called hemoglobin
Hemoglobin binds to oxygen to deliver and
release oxygen throughout the body
Some proteins protect cells
Proteins called enzymes speed up chemical
reactions in cells
CARBOHYDRATES
Molecules made of sugars
Cells use as source of energy an energy
storage
Simple carbohydrates – 1 or a few sugar
molecules – table sugar and sugar in fruits
Complex carbohydrates – organism has
more sugar than it needs - made of 100’s
of sugar molecules linked together
Plants (potato) store extra sugar as starch
LIPIDS
Cannot mix with water
Some store energy
Some form membranes of cell Phospholipids – membranes help protect
the cell and keep the internal conditions
stable
Fats and oils – store energy
Fats – most solid – most stored in animals
Oils – most liquid – most stored in plants
ATP
Adenosine triphosphate
Major energy-carrying
molecules in the cell
Energy in carbs and lipids
must be transferred to ATP,
which then provides fuel for
cells
NUCLEIC ACIDS
Blueprints of life
Information for a cell to make
proteins
Large molecules made up of
molecules called nucleotides
Order of nucleotides stores
information to make proteins
YOUR TASK
Write a job description for one of the
cell’s basic chemical building blocks.
Describe the required job
responsibilities. Include a
description of the expected workload
by explaining whether the building
block will have to work constantly or
sporadically. Indicate whether the
building block will work
independently or with other cell
components.
YOUR TABLE
Table
Table
Table
Table
Table
Table
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Proteins
Carbohydrates
Phospholipids
Fats and Oils
ATP
Nucleic acids