Introduction to Biology

Steps of the Scientific Method

1. Make an observation

2. Ask a question

3. Make a hypothesis

4. Experiment

5. Analyze data

6. Draw conclusion

Hypothesis

a scientific explanation that can be tested

Null Hypothesis

no effect or difference with the change

Independent Variable

the variable in an experiment that is purposely changed

Dependent Variable

directly affected by the independent variable

Constant Variable

quantities or variables that are the same in every group

Quantitive Data

data in the form of numbers, obtained by counting or measuring

Qualitative Data

data in the form of a description

Control Group

part of experiment that is not being tested; used for comparison

Positive Control Group

shows an already well known positive result to compare to

Negative Control Group

showing no result when none is expected for comparison

Experimental Group

the group with the independent variable

4 Ways to Improve the Validity of an Experiment

1. Increasing the amount of constants

2. Having a large sample size

3. Adding a control group

4. Repeating the experiment

Scientific Theory

a broad explanation that explains WHY or HOW events occur in the world

Scientific Law

description of observable phenomena in the world; explains WHAT happens in certain situations

8 Characteristics of Living Things

organization, DNA, reproduction, growth, energy, response, regulation, and evolutionary adaptation

Organization

all living things are made of cells (unicellular and multicellular)

DNA

living things have genetic material in the form of DNA

Reproduction

living things must produce new individuals called offsprings

Growth

living things grow by cells becoming larger or dividing to produce more cells

Energy

all living things need a source of energy; metabolism

Response

living things must respond to the environment that they are in

Regulation

organisms need to maintain homeostasis

Evolutionary Adaptation

living things change over a long period of time and certain changes; adaptation

Metabolism

use energy to break down and build up materials

Homeostasis

stable internal conditions

Adaptation

help them survive and reproduce

Biological Organization -Smallest to Largest

molecules, organelles, cells, tissues, organs and organ systems, organisms, populations, communities, ecosystems, biosphere

What 3 atoms make up a water molecule?

1 oxygen and 2 hydrogen

Polar

unequal sharing of electrons

Hydrogen Bonding

unequal sharing of electrons gives water the ability to make weak attractions to other water molecules

Covalent Bonds

atoms are connected by covalent bonds

Cohesion

water molecules being able to stick together (because of hydrogen bonds)

Adhesion

water molecules sticking to other stuff (not sticking to water)

Capillary Action

tendency of water to move along the surface of a substance due to adhesion; water molecules "pull" each other up

Surface Tension

special form of cohesion that causes the surface of water to resist rupture (reason why insects/critters can walk on water)

Universal Solvent

water can dissolve many substances sue to the partial charges within the water molecule

High Specific Heat

specific heat is the amount of heat energy needed to raise the temperature of water

Hydrophilic

substances that dissolve in water (water loving)

Hydrophobic

substances that do not dissolve in water (water fearing)

Macromolecules

large molecules that are critically important to all living things

Monomers

one unit of a macromolecule; joined together to form polymers

Polymers

strand of many monomers

Dehydration Synthesis

joining monomers together by removing water to create a bond

Hydrolysis

breaking down a polymer by adding water to break in a bond

Elements of a Carbohydrate

carbon, hydrogen, and oxygen

Monomer of a Carbohydrate

monosaccharide

Disaccharide

2 sugars

Polysaccharides

many sugars

Function of Carbohydrates

fast energy and structure

Carbohydrate Food Examples

candy, fruits, pasta, bread

Elements of a Lipid

carbon, hydrogen, and oxygen

Common Parts of a Lipid

(no true monomer) glycerol and fatty acids

Function of a Lipid

energy storage, forms cell membrane, and body insulation

Lipid Food Examples

vegetable oil, olive oil, coconut oil, butter, cheese, meats (bacon), avocado, nuts

Triglyceride (fats)

1 glycerol and 3 fatty acids

Saturated Fats

solid at room temperature (ex: butter)

Unsaturated Fats

liquid at room temperature (ex: oil)

Phospholipids

-forms the cell membrane of a cell

-contains a glycerol and phosphate group with 2 fatty acids

has 2 parts: head (hydrophilic) and tail (hydrophobic)

Elements of a Protein

carbon, hydrogen, oxygen, and nitrogen

Monomer of a Protein

amino acids

Structure of a Protein

-20 amino acids link together to form proteins

-long chain of amino acids is called polypeptides

-polypeptides fold into a protein

Function of a Protein

(little of everything) muscle contraction, cell transport, enzymes

Protein Example Foods

meats, nuts, eggs, beans

Elements of a Nucleic Acid

carbon, hydrogen, oxygen, nitrogen, and phosphorus

Monomer of a Nucleic Acid

nucleotide

Nucleotides

-the monomer of a nucleic acid

-three parts: sugar, phosphate group, and nitrogenous base

Function of a Nucleic Acid

sharing and transmitting instructions to make code for protein

Food Examples of a Nucleic Acid

all food has nucleic acids (all livings things have DNA and RNA)

Enzymes

proteins that speed up chemical reactions

Why are enzymes important?

enzymes speed up chemical processes by reducing the activation energy required to start the reaction

Enzyme examples

cellular respiration, photosynthesis, DNA replication, and protein synthesis

Chemical Reaction

changing substances by breaking and forming bonds (includes hydrolysis and dehydration reactions)

Activation Energy

the amount of energy needed to start a chemical reaction

Reactant

substances changed during a chemical reaction (substrate)

Product

the substance made by a chemical reaction

Steps during a chemical reaction

1st: the reactant (substrate) binds to a special part of the enzyme called the active site

2nd: the reactant takes place (making or breaking bonds)

3rd: the product is released from the enzyme and the enzyme remains unchanged

Denaturation

environment conditions cause enzymes to lose it's shape

Temperature with enzymes

can increase the rate of a reaction until the temperature is too high and denatures the enzyme

pH levels with enzymes

a pH level that is too low or high will cause an enzyme to denature (lose it's shape) and no longer work

Inhibitions with enzymes

inhibit the function of enzyme by binding to enzyme and preventing a substrate from properly binding