What is Life? Biochemistry: Chemistry of a specific process or art of living organisms.

Venn Diagram as a lab table. Compare characteristic of living and nonliving things. It must be true for all not just for some. Things to ponder…what do living things look like, act like, and have that nonliving things don’t. Next, in the middle section what is similar to both categories?

Life’s characteristics Energy Use- use to grow and repair injured parts Development- a process of change that occurs during an organisms life that produces a more complex organism Stimulus- a change in an organisms surroundings that causes a reaction. Response- an action or change in behavior Reproduce- produce offspring

Evolution?

Living Things..cont. 10 million different types of organisms on Earth. All composed of basic elements: carbon, hydrogen, nitrogen, and oxygen. Rules of interaction between these chemicals. Spontaneous Generation: theory by Francesco Redi (1668) that stated life could come from nonliving matter.

Redi’s Experiment 2 Jars filled with rotten meat One closed and one open Thus proving spontaneous generation is not possible. Life comes from NON LIVING things is NOT true!

Life as we know it…Video

Pasteur’s Experiment Clear broth into two flasks w/ curved necks Boil one set- killing the bacteria Didn’t boil the other and bacteria grew in it. Conclusion- New bacteria appears only when existing bacteria produces it.

Needs of Living things… Energy: primary source-sun Food: energy source as well, repair body parts. Water; few day without and death, chemical reaction/transport Oxygen: respiration Living space: enough food/etc Ability to maintain body temperature, homeostasis. Cold use movement.

Life…the beginning 4.6 billion years ago earth formed 1st Theory: Stanley Miller mixed hydrogen, methane, and ammonia-added an electrical current and found some building blocks of life. First living organisms arose- form early soup of chemicals. Little or no oxygen in earth’s early atmosphere.

2nd Theory..Trapped in the Clay 2nd Theory Other say chemicals in clay, chemicals that make-up life were found on Earth-ocean. Chemicals like carbohydrates, alcohols, and lipids also may have been in the “soup”. All living things began after “droplets” surrounded by clay walls over time became cells. Then Amino acids made when conditions are right: basic building blocks of life.

3rd Theory…Ocean Vents Life started in the chemical reactions within the hydrothermal vents located throughout the ocean floor (ridges) Bacterium is largest “bio” mass known to man. Larger than all of bio-mass of all living organisms on land. Life is living off of toxic, 760 degree F water using chemosynthesis.

Yellowstone Hydrothermal Vents

First Cells… Fossils indicate 3.5 billion years ago, did not require oxygen Plenty of food in the “soup” but when it ran out, producer cells evolved. Used chemicals from environment to produce food (energy and gases) Green plants produce food through photosynthesis Important: oxygen is a waste product

First Cells cont. Theory is just that, an educated guess. Consumers to Producers Cells that use Oxygen are more efficient in their production of energy. Unicellular (“uni” means one) Next came multi-cellular organisms and asexual or sexual reproduction.

History of Cells

Living things..chemical activities Metabolism: sum total of all chemical reactions in living things.( ex. Digest) Ingestion: take in food or produce their own. Digestion: process by which food is broken down into simpler substances Respiration: take in oxygen and use it to produce energy Excretion: getting rid of waste materials

Classification(taxonomy); the process of placing living organisms into categories based on similar characteristics. History: Aristotle fourth century B.C. Animals- appearance, behavior, and movement. 1750’s Carolus Linnaeus; categorized 12,000 organisms and gave each a two-word name: binomial nomenclature. Genus is the first word-closely related organisms, species is the second-can mate and produce offspring All latin words-easy for scientists to communicate

Today’s classification begins with Domain(Eukarya- cells with a nucleus, then sub divides them into kingdom, phylum, subphylum, class, order, family, genus, species. Dichotomous key-series of paired statements that describe the physical characteristics. Use to be Monerans- now Archaebacteria, Bacteria, and Eukarya contain: Protists, Fungi, Plants, Animals

Domains Bacteria  Prokaryotes cells without a nucleus Archaea “ancient”  Discovered at U of I, type of bacteria with DNA very diffferent in genetic make-up  Live in exstreme conditions  Ex. Yellowstone National Park in Hot Springs Eukarya  Cells have a nucleus  Protists, Fungi, Plants, Animals

Six Kingdoms- no longer used.