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1/21/2011
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Life Science
Chapter 3: Cell Processes1. Chemistry of Life2. Moving Cellular Materials3. Energy for Life
http://www.connecticutvalleybiological.com/cell‐processes‐vhs‐p‐14026.html
Chapter 3.1 Chemistry of Life
Learning Objectives:
1. List the differences among atoms, elements, molecules, and compounds.
2. Explain the relationship between chemistry and life science.
3. Discuss how organic compounds are different from inorganic compounds.
Vocabulary: mixture, organic compound, enzyme, inorganic compound
Matter…
• is anything that has mass and takes up space.
• Examples?
Energy …
• is anything that brings about change.
• can hold matter together or break it apart.
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Atoms
• All matter (whether solid, liquid, or gas) is made of atoms.
• Center of atom is called the nucleus.
The nucleus consists of:
• protons (have a + charge)
• neutrons (have no charge)
http://bioap.wikispaces.com/file/view/atom.jpg/107303887/atom.jpg
Atoms ‐ Electrons
• Around the nucleus is a cloud
of electrons (have a – charge).
• Constantly moving
• VERY small mass compared to protons and neutrons!
The mass of 1,837 electrons = the mass of 1 proton
• Involved in CHEMICAL REACTIONS
http://www.freaklasers.com/laser‐pointer/how‐laser‐works‐freaklasers‐1.jpg
Matter vs. Energy
Definition Examples
Matter atoms, electrons, protons, and neutrons; __________, __________, __________, __________, __________
Energy sunlight, electricity, heat, chemical energy
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Parts of an Atom
Electrical Charge? Location in Atom? Relative Mass?
Protons
Neutrons
Electrons
Elements…
• are made up of only one kind of atom.
• can’t be broken down into simpler form by chemical reactions.
• are known by their own one‐ or two‐letter symbol.
• make up everything in the
Universe.
http://www.walyou.com/blog/wp‐content/uploads/2009/07/periodic‐table‐elements‐au‐ring.jpg
http://static.howstuffworks.com/gif/periodic‐table‐2.jpg
http://facstaff.gpc.edu/~pgore/PhysicalScience/periodic‐table.gif
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How many of these elements can you identify?
O _____________
C _____________
H _____________
N _____________
Ca ____________
P _____________
K ______________
S ______________
Na _____________
Cl ______________
Mg _____________
Elements that make up the human body
99% of living matter……is made up of six (6) elements. That makes these elements pretty important!
S
P
O
N
C
H
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Compounds and Molecules
• Compounds ‐ composed of molecules
• Molecules of compounds have atoms of 2 or more elements bonded together.
• Example: water
http://kentsimmons.uwinnipeg.ca/cm1504/introchemistry.htmhttp://www.quarked.org/askmarks/images/water.jpg
Compounds and Molecules
• Compounds ‐ composed of molecules
• Molecules of compounds have atoms of 2 or more elements bonded together.
• These elements are in exact proportions.
• Example: Water is always made up of ___ hydrogen atom(s) and ___ oxygen atom(s), bonded together in exactly the same way, to form a water molecule.
Compounds and Molecules• Molecular Compounds form when different atoms share their outermost electrons.
Hydrogen atoms have 1 electron.How many electrons does an oxygen atom have? (see pg. 66)
– On Earth, Oxygen and hydrogen normally exist as gases.
– But as a compound (water), they can be liquid, solid, or gas.
**When a compound is formed, changes occur and a new substance forms.
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Organic and Inorganic CompoundsWhat’s the difference?
Characteristic ORGANIC COMPOUNDS INORGANIC COMPOUNDS
Contain elements:
Associated with:
Relative # of atoms:
Examples
Organic Compounds Found in All Living Things
There are four groups:
1.
2.
3.
4.
1. Carbohydrates
• Elements: carbon, hydrogen, oxygen
• Examples: sugars, starch, cellulose
• What function do they have?
1. Supply energy for cell processes
2. Form plant structures
3. Short‐term energy storage
http://www.fehd.gov.hk/english/safefood/nutrient/1.html
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2. Lipids
• Elements: carbon, hydrogen, oxygen, phosphorus
• Examples: fats, oils, waxes, phospholipids, cholesterol
• What function do they have?
1. Store large amounts of energy long term
2. Form major part of cell membranes
http://www.fehd.gov.hk/english/safefood/nutrient/1.html
3. Proteins
• Elements: carbon, hydrogen, oxygen, nitrogen, sulfur
• Examples: enzymes, skin, hair
• What function do they have?
1. Regulate cell processes
2. Build cell structures
http://www.fehd.gov.hk/english/safefood/nutrient/1.html
4. Nucleic Acids
• Elements: carbon, hydrogen, oxygen, nitrogen, phosphorus
• Examples: DNA & RNA
• What function do they have?
1. Carry hereditary information
2. Used to make proteins
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Inorganic Compounds
• Made from elements…
…other than carbon.
…that living things need.
• Example: Plants take up inorganic compounds from soil. These I.C. contain the elements nitrogen, phosphorus, and sulfur.
Some Inorganic Compounds Important in Humans:
http://www.fehd.gov.hk/english/safefood/nutrient/1.html
Compound Use in Body
Water Blood; chemical reactions
Calcium phosphate Bone strength
Hydrochloric acid Breaks down foods in stomach
Sodium bicarbonate Digestion
Salts containing S, Cl, and K Nerve messages
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Ch. 3.3 Energy for Life (p. 81)
Why It’s Important:
Because of photosynthesis and respiration, you use the Sun’s energy.
What You’ll Learn:
1. List the differences between producers and consumers.
2. Explain how the processes of photosynthesis and respiration store and release energy.
3. Describe how cells get energy from glucose through fermentation.
Vocabulary: metabolism, respiration, photosynthesis, fermentation
How do we get energy from the food we eat?
Chemical reactions!
• Food contains chemical energy.
• Using chemical reactions, cells change this chemical energy into forms needed to perform all of the activities necessary for life.
• All of your activities involve chemical reactions.
• Metabolism: The total of all chemical reactions in an organism.
• The chemical reactions in your cells need enzymes. Enzymes are like can openers.
• You need a can opener to open the can.• The can changes, but the can opener
doesn’t – it can be used over and over again.
Enzymes can break molecules apart (like a can opener), but enzymes also can cause molecules to join (unlike a can opener).
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BUT…just any old enzyme won’t do!
There has to be a perfect fit between a particular molecule and a particular enzyme.
http://www.skinnersbiology.co.uk/enzyme.htmhttp://isbibbio.wikispaces.com/Fungal+Amylase+‐+Baking+Enzyme
BUT…just any old enzyme won’t do!
There has to be a perfect fit between a particular molecule and a particular enzyme.
http://www.skinnersbiology.co.uk/enzyme.htmhttp://isbibbio.wikispaces.com/Fungal+Amylase+‐+Baking+Enzyme
Photosynthesis
Living things are divided into two groups based on how they obtain FOOD:
1.
2.
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Greek and Latin Word Roots Are Fun (and Useful!)
Photo means ____________.
Synthesis means ___________ ____________.
Photosynthetic Protists
Algae
http://en.wikipedia.org/wiki/Seaweedhttp://scienceblogs.com/clock/2006/07/biological_clocks_in_protista.php
Euglena
http://www.biologie.uni‐hamburg.de/b‐online/library/webb/BOT311/Cyanobacteria/Cyanobacteria.htm
Cyanobacteria
Stromatolites formed by cyanobacteria ‐Ancient oxygen producers3.5 billion years old!
Photosynthetic
Bacteria
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Photosynthesis During photosynthesis, producers use light energy to make sugars, which can be used as food.
_________________is a green pigment that captures sunlight energy. It’s what makes green plants green! In plants, this pigment is found in organelles called ___________________.
Raw Materials:
Captured by chlorophyll, the Sun’s energy
drives chemical reactions…
Sugar
Oxygen Water (from soil)
Carbon Dioxide (from air)
Products:
PHOTOSYNTHESIS IN PLANTS
http://www.topnews.in/law/region/london?page=146
CO2 + H2O + light energy C6H12O6 + O2Chlorophyll
http://batizybiologya.blogspot.com/
(Don’t forget the enzymes!)
What kind of organic compound is SUGAR?
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Storing Carbohydrates• Plants make more sugar than they need to survive.
• Excess sugar is changed and stored as starches or used to make other carbohydrates.
• Plants use these carbohydrates as food for growth, maintenance, and reproduction.
What about food we eat?
How is it connected to photosynthesis?
http://bio8.wikispaces.com/3)+The+Cell
http://www.uic.edu/classes/bios/bios100/lectures/ps01.htm
Respiration
During respiration, chemical reactions occur that break down food molecules into simpler substances and release their stored energy.
• Respiration occurs in the cells of all living things.
• Most cells need oxygen to break down food.
• Enzymes are also needed for the chemical reactions to occur.
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Respiration: Breaking Down Carbohydrates
• Out of all the types of food, carbohydrates are most easily broken down by cells.
– Respiration of carbohydrates begins in cytoplasm of cell.
– Carbohydrates broken down into glucose molecules
– Then each glucose molecule is broken down into two simpler molecules, releasing ENERGY.
Respiration, cont’dSo far…Carbohydrates glucose molecules two simpler molecules
• In mitochondria (most organisms), two simpler molecules broken down again using oxygen.
– Produces much more energy than breakdown of glucose molecules did
– Produces carbon dioxide and water as wastes (humans exhale these)
Fermentation
Not enough oxygen for respiration?
• Fermentation is used to release to release some of the energy stored in glucose molecules when cells don’t have enough oxygen.
– Example: when you run so hard that you have to breathe rapidly
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Process of Fermentation• Starts in cytoplasm (like respiration) and ends in cytoplasm (unlike respiration, which finishes in mitochondria)
• Like respiration, starts with breakdown of glucose molecules into simpler molecules to release some energy
• These simpler molecules are broken down again to release more energy, producing wastes.
– Wastes may include lactic acid, alcohol, and carbon dioxide
– Lactic acid makes muscles feel stiff
Fermentation in Action
http://www.brsquared.org/wine/Articles/MLF/MLF.htm
The Big Picture
How are the processes of photosynthesis, respiration, and fermentation related?
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