UNIT 1 – UNDERSTANDING LIFE ON EARTH

What qualifies something as living?• Organisms are made up of cells • Organisms reproduce sexually or asexually and some can

do both• Organisms will have a genetic code, DNA• Organisms will grow and develop• Organisms will obtain and use energy• Organisms will respond to their environment• Organisms will strive to maintain homeostasis• Organisms will change over time

Discussion

• What kinds of cells?• What is an example of asexual reproduction?• What is an example of sexual reproduction?• If all organisms have DNA is that DNA identical?• What is the difference between grow and develop?• What are 2 ways organisms obtain energy?• What does homeostasis mean?• What if living things do not adapt to changes in their

environment?

Answers:• Prokaryote-bacteria Eukaryote-plant , animals• Mitosis is asexual reproduction• Meiosis is sexual reproduction• No the DNA is not identical, except in identical offspring.

There are similarities but variation in the species• Growth is to add more cells, Develop is to mature into

and adult• Organisms can obtain energy by being either an

autotroph or heterotroph • Homeostasis means same-state. Organisms need to

maintain a stable internal environment in the body• If an organisms does not adapt to changes in the

environment then they must change the environment or die

Evolution• Can be sudden or gradual• Sudden changes that interrupt the gradual progress is called

Punctuated Equilibrium. • Explanation:• https://www.youtube.com/watch?v=6QiRoO8af7s

Levels Life is organized • Atoms• Molecules• Cells *life begins here• Tissue• Organ• Organ System• Organism• Species• Population• Community • Ecosystem• Biosphere

INTRO TO BIOCHEMISTRY

What elements from the periodic table support all life on Earth?Answer:•CARBON•HYDROGEN•OXYGEN•NITROGEN•PHOSPHORUS

8

Periodic Table of Elements

• Highlight the following element on your Periodic Table. The table should be glued in on the Left. • Carbon• Hydrogen• Oxygen• Nitrogen• Phosphate• Sulfur

Carbon-based Molecules:

10

Organic chemistry: study of carbon compounds

Carbon has 4 electrons in an outer energy level that holds eight; Can form 4 covalent bonds with many other elements

Shape of Organic Molecules:

shape=function

11

The shape determines

its function in

an organism

Giant Molecules – Polymers:•Large molecules are called polymers

12

• Monomers link together to form larger molecules called polymers

• Biologists call polymers macromolecules or biomolecules

Linking Monomers:

13

Cells link monomers by removing a molecule of water

Remove H

Remove OH

H2O Forms

this process is called dehydration synthesis.

Breaking Down Polymers:• Cells break down macromolecules by adding a molecule of water• this process is called hydrolysis

14

Macromolecules in Organisms:There are four macromolecules:

15

Carbohydrates (CHO)

Lipids (CHO)

Proteins (CHON)

Nucleic Acids (CHONP)

CARBOHYDRATES

16

Monosaccharides:•Monosaccharides are the monomers of carbohydrates; also called simple sugars• Examples: glucose, fructose, & galactose• Chemical Formula for monosaccharides is C6H12O6; this a ratio of 1:2:1

•Monosaccharides are the main fuel that cells use for cellular work; they are a source of quick energy•Disaccharides (2 Sugars bonded); example – sucrose (table sugar)

Polysaccharides:

Large sugar molecules; take longer for body to break down•Starch is an example of a polysaccharide in plant cells•Glycogen is a polysaccharide found in animal cells• Starch and glycogen are extra amounts of sugar taken in by the cell and stored for later use•Cellulose is a polysaccharide found in plant cell walls; most abundant organic compound on earth

18

LIPIDS

Lipids:• Lipids are hydrophobic –”water fearing”; they do not mix with water• Includes fats, waxes, steroids and oils• Functions –store energyInsulate bodyCushion and protect organsForm cell membranes

20

Structure of Lipids:• Triglyceride - Monomer of lipids Composed of 1 glycerol molecule and 3 fatty acid chains Glycerol forms the “backbone” of the triglyceride• Triglycerides are composed mainly

of carbon and hydrogen; oxygen is found only in the glycerol molecule

21

22

•Most animal lipids exist as solids at room temperature (butter, lard, fat layer on steak/chicken, waxes)

•Most plant lipids tend to exist as liquids at room temperature (peanut, sunflower, canola oils)

Lipids in Organisms:

Lipids & Cell Membranes:• Cell membranes are made of phospholipids

• Phospholipids have a head that is polar; it attracts water (hydrophilic)

• Phospholipids also have 2 tails that are nonpolar and do not attract water (hydrophobic) 23

Steroids:• Cholesterol is the

“base steroid” from which your body produces other steroids

• Estrogen and testosterone are examples of these other steroids

24

PROTEINS

Proteins:• Proteins are large, folded polymers made of monomers called amino acids• Elements in proteins: C, H, O and N• Functions:Build cellsAct as hormonesAct as enzymesCellular transport

26

Linking Amino Acids:•This process is done by the ribosomes in the cell by removing a water molecule from the amino acids•The process is called a condensation or dehydration reaction; forms peptide bonds

27

Enzymes are proteins

•What do enzymes do?• Enzymes control the rate of chemical reactions• Enzymes are also referred to as biological catalysts• enzymes work by weakening bonds and lowering the amount of activation energy needed for the reaction

• Enzymes act on a substrate; they are specific to substrate

28

Enzyme + Substrate = Product:

29

NUCLEIC ACIDS

Nucleic Acids

•Store hereditary information

31

• Contain information for making all the body’s proteins

• Elements in nucleic acids: C, H, O, N and P

• Types of nucleic acids: DNA and RNA

•Nucleic acids are polymers; Nucleotides are the monomers•Nucleotides are composed of: 5-carbon sugar phosphate group nitrogeneous base

Nitrogeneous Bases:

•Each DNA nucleotide has one of the following bases:

• Each RNA nucleotide has one of the following bases:

–Adenine (A)

–Guanine (G)

–Uracil (u)

–Cytosine (C)33

–Adenine (A)

–Guanine (G)

–Thymine (T)

–Cytosine (C)

Shape of dna and rna:• One strand of

RNA forms a single helix

• Two strands of DNA join together to form a double helix

34

ATP

•ATP is the energy currency of cells

•Made of a nucleotide with 3 phosphate groups

35