BIOL 101 LIBERTY UNIVERSITY Unit_1_Study_Guide_STUDY MATERIAL_2024.pdf

Study Guide for Biol 101—002 Spring 2019

Chapter 1: Know the following material

6 characteristics of living things

Made Up of Cells- known to be the defining element of everything else (life) (trumps all)

Reproduce

Grow and Develop

Get and Use Energy

React to stimulus

Made up of Cells

Defines life

Trillions of cells

100 trillion cells

Evolution- is the theory that

What do cells look like?

Somewhat flat surface with “stuff” in it

Cells are three dimensional, what we are actually looking at within the cell

Reproduce

Mechanisms by which parents produce offspring

Often this occurs when a sperm fertilizes an egg

Before this can happen, DNA instructions and information must be passed on from cell to cell

The nucleus is the structure that houses the information deoxyribonucleic acid (DNA) is the

molecule that carries the information

Almost all life forms carry information this way

The structure of the DNA molecule allows for the information contained in the DNA is

precisely and efficiently passed on from cell to cell and from organism to organism

Results in the identity of a species being retained

Grow and Develop

A series of steps that transforms a single cell into a multi-celled adult

oWith cells arranged into tissues and organs

oEach specialized to accomplish a specific task

React to Stimulus

A stimulus is some kind of change in the environment that our senses pick up

It can be seeing, hearing, feeling, smelling, tasting

Viruses

Are made of protein and DNA, the host reproduces not the virus

Levels of Organization**********

Atom

Molecule

Organelles

Cells

Tissues

Organs

Organ systems

Organism

Atom- the smallest unit of matter, when atoms combine together covalent bonds

Biomolecule- DNA, proteins, carbs, fats

Organelles- structures within the cell with particular functions (ex. Nucleus)

Organs- collection of different types of tissues that together perform a function (example: heart)

Organ system- collection of organs that perform a particular function (example: circulatory, digestive)

Higher Levels of Organization ****

Multicellular organism

Population (species)

Community

Ecosystem

Biosphere

Populations- are all the members of a type of species that is located in a close enough area to

interbreed

Community- all of the populations living in a given area and their interactions

Humans in New York City

ohumans, cats, rats, geraniums, cockroaches, etc.

Ecosystems- all the populations (community) and their interactions with the non-bio (physical)

environment

Biosphere- all the ecosystems on and within planet earth (climate, rainfall, temperature, sunlight)

Scientific Names

Two-part naming system by Carolus Linnaeus

First name is genus (plural, genera)

oHomo sapiens- genus is Homo

Second name is species within genus

Categories of Biological Classification *******

Domain, Kingdom, Phylum, Class, Order, Family, Genus, Species

Categories of Biological Classification—from domains to species

oKnow the characteristics that describe organisms in each kingdom

oKnow Who came up with the scientific naming system

oKnow what is the scientific naming system is

Chapter 2:

The scientific method

Observe phenomenon-questions

Make a hypothesis (explanation)

oMake testable predictions

oDevise test of predictions

oDrives the experimentation

Carry out test

Analyze results

Draw conclusions

Repeat

Science is based on observation and experimentation

Hypothesis can never prove 100% correct, we can’t prove that a hypothesis is “true”

oWe can only provide evidence that it’s not wrong

What is/What it is not

What is: rational approach that is understanding life; dynamic and fluid process that leads closer

to the truth

What it is not: clear steps that always progress one to the other; objective path to absolute truth

Experimental Problems

Bias- experimenters already assumed ideas that influence how and what experiments are done

Sampling error- “non-representative” sample that skews results, too small or not consistent

total population, minimize by using large samples

Hypothesis, Theory, Law

Hypothesis- has been tested for its predictive power several times and has yet to be proved

wrong

Law- statement that summarizes observable behavior where there’s no known exceptions

oLaw of Conservation of Mass- chemical reaction, mass is neither created nor destroyed

Theory- explanation for an observation

oIn chemical reactions, bonds between atoms in a molecule broken and those atoms are

rearranged to form new bonds, making different molecules

Chapter 3: Know the following material

Structure of the Atom

Living cells are made of millions of atoms that make thousands of different molecules

Atoms are- the smallest unit of matter that retains property of the element

oMade of subatomic particles

Protons (+), Electrons (-), Neutrons (no charge)

Nuclear Model- the atom is mostly empty space, two regions, nucleus, surrounded by electrons,

called nuclear model

What are the four main elements that living things are made of?

Carbon, hydrogen, nitrogen, and oxygen

Physical Properties of Atoms

Atomic number- the number of protons (also indicates number of electrons)

oAn atom is neutral charge; it has the same number of protons and electrons

Mass number- number of protons + neutrons

Isotopes/radioisotopes- isotopes of an element differ in # if neutrons, radioisotopes emit

radioactivity *********

This can be found on the periodic table

Shell Model

Electrons have different energy levels

 First shell- lowest energy with 2 electrons

Second shell- 8 electrons

How do Atoms Interact?

All atoms want is to have 8 electrons in their outer shell of electrons (except hydrogen and

helium who want 2)

They accomplish this by either sharing or transferring electrons with another atom

This sharing or transferring electrons results in a bond, which is a force that holds atoms

together

Bonds

What are bonds? –

Three Important biological molecules- covalent, hydrogen, and ionic bonds

Chemical Bonds

Force that holds two atoms together

Ionic bond- formed by the giving/taking (transfer) of electrons; metal/non-metal

Covalent bond- formed by electrons being share; non-metal/non-metal

oResults in molecules

May contain atoms of only one element (02)

May contain more than one element (h20)

oPolar covalent- shared unequally, CN, H20

oNon-popular covalent (might just be called covalent)- shared equally, H2, O

Covalent Bonds

Atoms can share electrons

This occurs when the atoms are

oNon-metal/non-metal

Oxygen needs 2 hydrogen each need 1

In H20, each hydrogen shares 1 electron with the oxygen atom, so each H has 2

and the oxygen has 8

Results in a molecule (compound)

This type of bond is a covalent bond

Covalent Bonding-

Atoms share a pair of electrons to fill outermost shell

oSingle- covalent bond (1pr)

oDouble-covalent bond (2pr)

oTriple covalent bond (3pr)

Polar/Nonpolar

Polar

One atom is more electronegative (pulls harder on the electrons) than the other

Electrons spend more time near more electronegative atom

Water- electrons more attracted to 0 nucleus than H nuclei

Nonpolar

Atoms share electrons equally

Neither atom is pulling harder on the electrons than the other

oEx. Hydrogen gas (H-H)

Ionic Bonds

One atom loses electrons, becomes positively charged ion

Another atom gains these electrons, becomes negatively charged ion

Charge difference attracts the two ions to each other

Outermost electrons of one atom are transferred permanently to another atom

Hydrogen Bonds

Happens when two molecules (or two regions of a large molecule) held together by polar

covalent bonds

More electronegative atoms of one molecule (oxygen or nitrogen pull on electropositive

hydrogen atoms

Forms a weak bond, but many together can be very strong

Does NOT make a new molecule

Chemical Bookkeeping

See what number each electron has

Reactants----Products

Water

Everything that we do is dependent on water

Cleaning, cooking, transportation

60-90% of humans’ bodies

About 70% the earth’s surface is water

We need to drink it; plants have to have it

Properties of Water- are due to polar nature, water is a polar covalent molecule

Density decreases when frozen therefore ice floats

Universal solvent

Cohesive (water molecules are attracted to each other)

oThis drives capillary action-transpiration in plants

oIts why oil and water don’t mix!

Stabilizes temperature

oH-bonding disrupted instead of molecular motion

oEvaporation

the colder it gets or lower the temperature the more atoms are attracted to one another

Acids and Bases

Acids

oDonate H+ when dissolved in water

Ex. HCL (hydrochloric acid) H+ and Cl-

Bases

oAccept H+ when dissolved in water

Ex. NH3--------NH4+

oOr releases OH- in water

Ex. NaOH Na+ and OH-

The pH Scale

Ranges from 0 to 14, it measures the H+ concentration of fluid

0-7 is acidic (smaller number is the more acidic it is)

7 is neutral

Above 7 to 14 is basic (larger number=more basic)

Highest H+ Lowest H+

0---------------------7-------------------14

Acidic Neutral Basic

Weak Acids

Weak acids

oReluctant H+ donors

oCan also accept H+ after giving it up

oCarbonic acid (H2CO3) is example- this is in soda

Strong acids

oCompletely give up H+ when dissolved

oHydrochloric acid (HCI) is an example

Buffer System

When blood pH rises (less acidic), carbonic acid dissociates to form carbonate acid dissociates to

form bicarbonate and H+

oH2CO3----------HCO3 + H+

When blood pH drops (more acidic), bicarbonate binds H+ to form carbonic acid

oHCO3- +H+ ---------H2CO3

Chapter 4: Biological Molecules- Carbon Compounds

Biological Polymers

Life depends on polymers of carbon compounds

They allow complicated structures to form a small number of monomers

Simplify the genome

Makes break-down and reassembly less complicated

Carbon Compounds

Hydrogen, other elements, and functional groups covalently bonded to carbon

oCarbohydrates- sugars, starches, fibers

oLipids- oils, cholesterol

oProteins- meat, enzymes

oNucleic acids- DNA, RNA

How Carbon Forms Bonds

Outer shell of carbon has 4 electrons, but hold 8

Each carbon atom can form bonds up to 4 120 degrees apart

Can form chains or rings

Atoms cluster and covalently bonded to carbon backbone

Condensation vs. Hydrolysis

Hydrolysis *****

Polymers (complex)----- monomers (subunits)

Breaking down reactions (=water cutting)

Enzymes split molecules into two or more parts

An -OH group and -H atoms derived from water are attached at exposed sites

Condensation Reactions

Monomers (subunits) ----- polymers (complex)

Building reactions

Enzymes removes -OH from one molecule, -H from another and then forms a bond between two

the 2 monomers

Discarded atoms join to form water

Functional Groups

Hydroxyl group -OH

Amino group -NH2

Carboxyl group -COOH

Phosphate group- PO4

Carbonyl group -CO- or -CHO

Four Biological Polymers

Carbohydrates (sugars, starches, cellulose chitin)

Proteins (enzymes)

Lipids (fatty acids)

Nucleic acids (DNA, RNA)

Carbohydrates

Monosaccharides *

oSimple sugars

Disaccharide *

o2 monomers=disaccharide

Oligosaccharides*

o(short-chain carbohydrates)

o3-10 monomers

Polysaccharides *

o(complex carbohydrates)

o> 10 monomers

oFour mains: starch, glycogen, cellulose, and chitin *



Proteins

Chain of amino acids linked by peptide bonds

What are the four levels of protein structure? *

oPrimary, secondary, tertiary, and quaternary

Peptide bond

Peptide bond- covalent bond that links one amino group to one amino acid with

carboxyl group of the next

oForms through condensation reaction

Denaturation

oHeat (temperature) can denature a protein

opH

oheavy metals

Lipids

Mostly fatty acids

Four types: fats, phospholipids, waxes, and oils

oTriglycerides and phospholipids contain fatty acids

Insoluble in water *

Two parts of fatty acid chain

oGlycerol and fatty acid

Saturated- single bonds between carbons (animal fats)

Unsaturated- one or more double bonds (plant fats-vegetable oils)

Nucleic acids

Nucleotides

Energy Carries (ATP)

Electron Carries (NAD+, FAD+)

Genetic Material (DNA and RNA polymers)

Chemical Messengers (Cyclic AMP)

Which nucleic acid stores energy?

ATP stores energy

Basic strand of a DNA molecule

Double-stranded

Four types of nucleotides

oATCG

oA—T and C----G

RNA

Single stands

Have four types of nucleotides

oAdenine, guanine, thymine, cytosine

BIOL 101 LIBERTY UNIVERSITY Unit_1_Study_Guide_STUDY MATERIAL_2024.pdf

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