BIO 101 Class 2 Notes

2020 BIO 101 Class 2 Notes • Evolution

• 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

• 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

• 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

• 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 change are powerful selective forces that affect the evolution of many species, including • Antibiotic-resistant bacteria • Pesticide-resistant bacteria https://www.coursehero.com/file/79445740/BIO-101-Class-2-Notespdf/ This study resource was shared via CourseHero.com

• Endangered species, and • Increasing rates of extinction

• 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

• 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

• 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

• Cells add monomers together to form polymers via a

Dehydration reaction

• 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 https://www.coursehero.com/file/79445740/BIO-101-Class-2-Notespdf/ This study resource was shared via CourseHero.com

▪ When used for fuel, molecules are released from body in some way • Carbs usually used for fuel • 2 glucose make a Maltose

• 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

• Different form of glucose

• Cellulose: plant cell walls

• Most abundant organic compound on earth
• Don’t have enzymes to chemically break it down

▪ Called insoluble fiber, the stuff that passes straight through

• Chitin: insects and crustaceans exoskeleton

• The crunchiness when you step on a cockroach hahah

• When you work out, you transfer glycogen to glucose and it will lower your hunger

• 3.8 Fats are lipids that are mostly energy-storage molecules

▪ Lipids • Refer to fats, phospholipids, and steroids • Water insoluble (hydrophobic) long-term energy storage, • 2x energy as polysaccharide • Not from monomers • Major component of cell membranes

• Some vitamins cant dissolve without fats so if you don’t eat a

meal with fats, you can’t dissolve and absorb the vitamins causing a nutrient deficit • Unsaturated fatty acids

• Have kinks in the chain causing it to be liquid at room

temperature

• One fewer H atom on each carbon due to a double bond

• Saturated fatty acids

• solid at room temperature
• have maximum number of H atoms

• When unsaturated fats converted to saturated fats by adding Hydrogen, it creates trans fats

• Trans fats very unhealthy
• 3.9 Phospholipids and steroids: a variety of functions https://www.coursehero.com/file/79445740/BIO-101-Class-2-Notespdf/

This study resource was shared via CourseHero.com

▪ Phospholipids are the major component of a cell membrane • Phospholipids are composed of hydrophilic heads and hydrophobic tails

• Heads comprised of the phosphate group and glycerol

▪ Cholesterol- common component of animal membranes and component of steroids

• Example of steroid hormone: testosterone, estrogen

▪ Need fats to make your hormones so without them you can’t make sex hormones

o 3.10 CONNECTION: Don’t mess with hormones!

• 3.11 Proteins from amino acids linked by peptide bonds

▪ Proteins: polymers of 20 amino acid monomers

▪ Polypeptide amino acid sequence causes shape => function

▪ 3-dimentional shape: tertiary structure from interactions of side groups

▪ (most) Enzymes are proteins: metabolic catalysts regulate cell’s chemical

reactions

• PEPTIDE AND POLIPEPTIDE BONDS
• 3.12 A protein’s specific shape determines its function

▪ Proteins grooves are important ????▪ Denaturation: polypeptide chain unravels, loses its shape, therefore its function • Proteins can be denatured by changes in salt concentration, pH, or by high heat

• 3.14 DNA and RNA are the two types of nucleic acids

▪ The amino acid sequence of polypeptides is programmed by unit of inheritance: gene ▪ DNA (DeoxyriboNucleic Acid), a nucleic acid • Inherited • Directions for its own replication • Programs cell’s activities by directing protein synthesis ▪ DNA does not build proteins directly ▪ DNA works through an intermediary, RiboNucleic Acid (RNA) • DNA is transcribed into RNA • RNA is translated in proteins ▪ Where is this information?• DNA actually carries the information and is located in the nuclei

• 3.15 Nucleic acids are polymers of nucleotides

▪ DNA and RNA (ribonucleic acid) monomers are nucleotides

• 5-carbon sugar:

• (ribose) RNA
• Deoxyribose DNA,

• Phosphate group • Nitrogenous (nitrogen-containing) base https://www.coursehero.com/file/79445740/BIO-101-Class-2-Notespdf/ This study resource was shared via CourseHero.com