BIO 101 Class 2 Notes updated 2020

BIO 101 Class 2 Notes updated 2020
 Evolution
o The unity of life is based on DNA and a common genetic code
 The diversity of life arises from differences in DNA sequences
 Life has a unity and diversity
o The diversity of life can be arranged into 3 domains
 Bacteria are the most diverse and widespread prokaryotes
 Single celled ??
 Archeae are prokaryotes that often live in Earth’s extreme environments
 Single celled with no nuclei
 Eukarya have eukaryotic cells and include
 Single-celled protists and
 Multicellular fungi, animals, and plants
o 1.7 Evolution explains the unity and diversity of life
 From his observations, Darwin inferred
 Individuals with heritable traits best suited to environment more likely
to survive and reproduce
 This unequal reproductive success over many generations, an
increasing proportion of individuals with advantageous traits
 Result: evolutionary adaptation, accumulation of favorable traits in a
population over time
o Same adaptations would only occur with same weather and
outside factors
o 1.11 EVOLUTION CONNECTION: evolution is connected to our everyday lives
 Human-caused environmental changeare powerful selective forces that affect
the evolution of many species, including
 Antibiotic-resistant bacteria
 Pesticide-resistant bacteria
 Endangered species, and
 Increasing rates of extinction
o Technology evolves by the same kinda process, natural selection
by consumers
 New variations don’t come about from climate changes, climate
changes simply bring out already occurring adaptations
 Molecules
o Objectives
 Explain how a cell can make large molecules from a small set of molecules
 Define polysaccharides and explain their functions
 Define lipids, and explain their functions
 Describe the chemical structure of proteins and their importance

,  Describe the chemical structure of nucleic acids and how they relate to
inheritance
 Explain how lactose tolerance has evolved in humans
o 3.3 Cells make large molecules from a limited set of small molecules
 4 classes of molecules important to organisms
 Carbohydrates
 Proteins
 Lipids
 Nucleic acids
 Macromolecules
 Polymers= made from building blocks (called monomers) strung
together
o Cells add monomers together to form polymers via a
Dehydration reaction
o Hydrolisis is the process by which macromolecules and
polymers are broken down into the smaller parts
 Both reactions require the help of enzymes to make or
break bonds
 Reactions mediated by enzymes, which speed up chemical reactions in
cells
o 3.4 Monosaccharides: simplest carbohydrates
 Monosaccharides
 Form rings in aqueous solutions
 Cellular fuels
 Incorporated into other organic molecules
 Ex. Glucose
 Food for an organisms is anything that provides energy
and material for building new molecules
 When used for fuel, molecules are released from body
in some way
 Carbs usually used for fuel
 2 glucose make a Maltose
o 3.5 2 monosaccharaides link to form a disaccharide
o 3.7 polysaccharides: long chains of sugar units
 Polysaccharides of glucose monomers
 Polysaccharides are macromolecules made by hundreds of polymers
 Starch: plant energy storage
 Glycogen: animal energy storage
o Different form of glucose
 Cellulose: plant cell walls
o Most abundant organic compound on earth