AP Biology: Unit One

Independent Variable (x)

the factor that is manipulated or changed by the researcher

Dependent Variable (y)

the factor that is measured and is expected to change in response to the independent variable

Alternative Hypothesis

Predicts there is a relationship between two variables

Null Hypothesis

Predicts there’s NO relationship between two variables

Inductive Reasoning

Moves from specific observations to broader generalizations

Deductive Reasoning

A general premise or theory and moves to a specific, certain conclusion

Standard Deviation

Measures the dispersion of individual data points within a single sample or population

Standard Error

Measures the accuracy of a sample mean as an estimate of the true population mean

Calculating Standard Deviation

Calculating Standard Error

Is a Large or Small Standard Error Desired? Why?

A small standard error is desired because it indicates a more precise and reliable estimate of the true mean

What does overlap in error bars indicate?

There isn't a statistically significant difference between the data sets

Atomic Number (Left, Top)

the number of protons in the nucleus of an atom, which determines the chemical properties of an element and its place in the periodic table.

Atomic Mass (Bottom)

the mass of an atom of a chemical element expressed in atomic mass units. It is approximately equivalent to the number of protons and neutrons in the atom (the mass number) or to the average number allowing for the relative abundances of different isotopes.

How is the number of neutrons calculated?

Atomic Mass - Atomic Number

Ionic Bond

involve the transfer of electrons between atoms, forming positively and negatively charged ions that are attracted to each other

Covalent Bond

involve the sharing of electrons between atoms to achieve stability

Polarity

molecules have an uneven distribution of electron density, creating partial positive and partial negative charges

Nonpolarity

molecules have an even distribution of electrons, with no significant partial charges

If there’s cohesion, is there more or less polarity?

More Polarity

Positive Charge

more protons than electrons

Negative Charge

more electrons than protons

DNA nucleotide consists of what?

Phosphate, Pentose, Nitrogenous Bases

Phosphate

Molecules containing phosphorous and oxygen that gives the nucleotide a negative charge and forms the backbone of DNA

Pentose

A 5-Carbon Sugar (deoxyribose) which provides structural frame for the nucleotide and the DNA molecule

Nitrogenous Bases

Adenine → Thymine

Cytosine → Guanine

Bacteria

Eubacteria

Archaea

Archaebacteria

Eukarya

Protista, Fungi, Plantae, Animalia

Domain Differences: Bacteria

Prokaryotic (No Nucleus)

Cell Wall: Peptidoglycan

Single Cellular DNA

Asexual

Domain Differences: Archaea

Prokaryotic (No Nucleus)

No Peptidoglycan

Single Cellular DNA

Asexual

Domain Differences: Eukarya

Eukaryotic (Nucleus)

Cell Wall Sometimes

Linear DNA

Asexual/Sexual

Carbohydrate Function

Quick Energy

Carbohydrate Components

Monomer: Monosaccharide

Polymer: Polysaccharide

Elements: C,H,O

Lipid Function

Long-Term Stored Energy, Cell Membranes

Lipid Components

Monomer: Fatty Acids

Polymers: Triglycerides, Phospolipids

Elements: H,C,O

Protein Function

“Work Horses” - Muscle, Antibodies, Enzymes

Protein Components

Monomer: Amino Acids

Polymers: Protein (Polypeptide)

Elements: C,H,N,O, SOMETIMES: S

Nucleic Acid Function 

Store and express genetic information

Nucleic Acid Components

Monomer: Nucleotide

Polymers: N.A. —> DNA/RNA

Elements: N,C,H,O,P

Nucleic Acid: Pyrimadines

One nitrogen ring

Nucleic Acid: Purines

Two nitrogen rings

Nucleotide

Bases, Sugar, Phosphate

Nucleoside

Bases & Sugar 

DNA

Stable, Double Stranded, Deoxyribose, ONE OXYGEN

RNA

Less Stable, Single Stranded, Ribose, TWO OXYGEN

When is a fatty acid saturated?

No double bonds

When is a fatty acid unsaturated?

Double bonds

Highly electronegative atom on the end of an R-group

Polar Amino Acid

A series of hydrocarbons on the end of an R-group

Nonpolar Amino Acid

Are nonpolar amino acids more likely to be found on the interior or exterior of a globular protein that exists in the cytosol of a cell?

Interior because they are hydrophobic

Are polar amino acids more likely to be found on the interior or exterior of a globular protein that exists in the cytosol of a cell?

Exterior because they’re hydrophilic 

Steroids

Multiple rings of carbon atoms connected together

Triglyceride

3 fatty acids

What does too much triglyceride indicate?

Indicator of heart disease

Are phosphate groups polar or nonpolar?

Polar

Are fatty acids chains polar or nonpolar?

Nonpolar

Cell Distinctions: Prokaryotic

• No Nucleus

• Lack Membrane Bound Organelles

• Single Circular Chromosomes

• Asexual

• Smaller

Cell Distinctions: Eukaryotic

• Nucleus

• Contain Membrane Bound Organelles

• Linear Chromosomes

• Asexual/Sexual

• Larger 

Taxonomy

The scientific discipline of identifying, naming, describing, and classifying living organisms into a hierarchical system based on shared characteristics.

Domain

Kingdom

Phylum

Class

Order

Family

Genus

Species

Natural Selection

The process where organisms with traits that help them survive and reproduce in their environment tend to pass those beneficial traits on to their offspring, leading to changes in a population over generations

Correct Sequence of Life’s Hierarchy

1. atoms/molecules

2. organelles

3. cells

4. tissues

5. organs

6. organisms

7. communities

8. populations

9. ecosystems

10. biosphere

Cation

positively charged ion formed when an atom loses electrons, making it have more protons than electrons.

Anion

negatively charged ion formed when an atom gains electrons, resulting in more electrons than protons

Why are water molecules attracted to each other? What is this called?

Cohesion: Water molecules are polar, meaning they have a slight positive charge on one end (the hydrogen atoms) and a slight negative charge on the other end (the oxygen atom). The positively charged hydrogen atom of one water molecule is attracted to the negatively charged oxygen atom of a nearby water molecule. 

What property of water allows a water strider to walk on its surface?

the high surface tension of water, which results from the cohesive forces between water molecules.

Dehydration

a chemical process where two smaller molecules (monomers) bond together, forming a larger molecule (a polymer) while simultaneously releasing a molecule of water as a byproduct

Properties of Water that Demonstrate Why Water is Essential to Life

• Cohesion

• Adhesion

• Specific Heat

Cohesion

is the force of attraction between molecules of the same substance, leading to properties like surface tension and water droplets forming a sphere.

Adhesion

is the force of attraction between molecules of different substances, enabling actions like glue sticking to paper or water clinging to plant tissues

Specific Heat

the quantity of heat required to raise the temperature of one gram of a substance by one Celsius degree

Essential Elements of Life

carbon

hydrogen

nitrogen

oxygen

phosphorus

sulfur

Hydrophobic

referring to substances, usually nonpolar, that repel water and do not readily mix with it, instead forming separate layers or droplets

Hydrophilic

describing substances that readily mix with or are attracted to water, typically due to polar or charged groups that form hydrogen bonds

Hydrolysis

a chemical reaction where a molecule is split into two parts by the addition of water, with the water molecule itself breaking into a hydrogen ion (H+) and a hydroxide ion (OH-)