AP BIOLOGY - 1st Semester Review

Independent variable

The experimental factor that is manipulated. The variable whose effect is being studied.

dependent variable

The outcome factor. The variable that may change in response to manipulations of the independent variable.

polar covalent bond

A covalent bond in which electrons are not shared equally.

nonpolar covalent bond

A covalent bond in which electrons are shared equally

What 4 elements make up 96% of living matter?

Carbon, Hydrogen, Oxygen, Nitrogen

How many elements are essential for human life?

25 elements are essential for humans.

What elements make up the other 4% of elements in living organisms?

Phosphorus, sulfur, calcium, potassium

What other element is needed by every living organism?

Iron

Hydrogen bonds (in water)

weak attraction between a hydrogen atom (partially positive) of one water molecule and the oxygen (partially negative) atom of another water molecule

Covalent bond

chemical bond that involves SHARING a pair of electrons between atoms in a molecule (two nonmetals)

Ionic bond

chemical bond resulting from the attraction between oppositely charged ions (metal and nonmetals). electrons are donated/transfered from one atom to another.

Electronegativity

measures the tendency of an element to attract electrons toward itself

Which is more electronegative, oxygen or hydrogen?

oxygen is more electronegative than hydrogen. it oulls hydrogen towards it.

Why is WATER POLAR?

the oxygen atom has a slight negative charge and the 2 hydrogen atoms have a slight positive charge. unequal distrubution co electrons.

What bonds connect oxygen and hydrogen in a single water molecule?

Polar covalent bonds

Cohesion

an attraction between molecules of the same substance

Adhesion

attraction between molecules of different substances

How does water go up a tree?

Adhesion of water to cell wall helps it resist gtavity. Cohesion of water to itself helps hold water together as it travels.

high specific heat meaning

it takes more energy to increase the temp of water than other liquids

What are the benefits of water having high specific heat?

It can take in lots of heat from the sun without changing in temp too much, so it remains as a good environment for aquatic animals.

heat of vaporization

the amount of heat/energy required for the liquid at its boiling point to become a gas

Benefits of water's high heat of vaporization

Moderates earth's temperature

evaporative cooling

As water evaporates, the surface of the liquid that remaijs behijd cools down (temp decreases) and this happens because the molecules with the highest kinetic energy are the most likely to leave as a gas.

pH means ...

power of hydrogen

0-6 pH

acid, more H+ than OH-

7 pH

neutral, H+ = OH-

8-14 pH

basic (alkaline), more OH- than H+

If the pH of a lake is 4.0, what is the hydrogen ion concentration of the lake and hydroxide concentration of the lake?

H+ = 1 x 10^-4 M, OH- = 1 x 10^-9 M

why can carbon can form so many diverse molecules?

It can bind up to 4 different molecules

What were the results of the experiment done by Stanley Miller & Harold Urey?

it was possible to recreate organic molecules under chemical conditions that were similar to that of the early earth.

Hydrocarbons

Compounds composed of only carbon and hydrogen

Isomers

Two different molecules that have the same chemical formula

Structural isomers

Same molecular formula, differ in the covalent arrangements of their atoms

cis-trans isomers

Same molecular formula, functional groups are placed on different sides of the double bond (cis side has two of the same thing, trans side has them two different molecules next to eachother in every orientation)

Enantiomers

isomers that are mirror images of each other (complete mirrors!)

Hydroxyl

-OH, polar

Carbonyl

\>C=O, polar

Carboxyl

-COOH, polar, weak acid

Amino

-NH2, polar, weak base

Sulfhydryl

-SH, polar

Phosphate

-OPO3^ 2-, polar

Methyl

CH3, nonpolar and hydrophobic (only nonpolar functional group! Methyl is mehh)

What chemical change occurs to ATP when it reacts with water and releases energy?

The ATP molecule loses a phosphate, becoming ADP (releases energy)

Monomer

A simple compound whose molecules can join together to form polymers

Polymer

A long molecule consisting of many similar or identical monomers linked together.

dehydration synthesis

chemical reaction in which two molecules covalently bond to each other with the removal of a water molecule.

Hydrolysis

the chemical breakdown of a compound due to reaction with water.

Monosaccharides

Single, simple sugars like glucose, fructose, galactose (both g and the f, just not glycogen but thats big so remember that)

Disaccharide

double sugar, consisting of two monosaccharides joined by dehydration synthesis, like sucrose, lactose, maltose

Polysaccharides

Carbohydrates that are made up of more than two monosaccharides, like starch, cellulose, glycogen

starch, glycogen, cellulose, chitin

examples of polysaccharides

function of starch and glycogen

energy storage in plants (starch) and animals (glycogen)

What bonds link together monosaccharides?

Glycosidic linkages

Protein

macromolecule that contains carbon, hydrogen, oxygen, and nitrogen; needed by the body for growth and repair

functions of proteins

structural support, catalyst for chemical reactions, transporting substances through the cell, defense against viruses, movement of substaces throughout the cell, regulation

Lipids

Energy-rich organic compounds, such as fats, oils, and waxes, that are made of carbon, hydrogen, and oxygen.

function of lipids

long term energy storage, make up cell membrane

Carbohydrates

the starches and sugars present in foods

Function of carbohydrates

store energy and provide structural support

nucleic acids

DNA and RNA

Function of nucleic acids

store and transmit genetic information

What parts make up an amino acid

Central carbon, carboxyl (x cus acid is bad) group, amino group, and varying R group

What bonds hold together amino acids?

peptide bonds

Phospholipid

hydrophilic head with phosphate group and hydrophobic tail made of saturated/unsatured fattyacid tails

Fat molecule

Glycerol and fatty acids

Fatty acids are made of what

Long carbon chain

unsaturated vs saturated fatty acid

saturated = single carbon bond (solid at room temperature) (saturated, single, solid), unsaturated = double carbon bond (liquid at room temperature)

How do polypeptide chains form?

2 amino acids link by ehydration synthesis (peptide bonds join them)

primary structure of protein

Linear chain, sequence of amino acids

secondary structure of protein

Regions of repetitive coiling or folding of the polypeptide backbone of a protein are stabilied due to hydrogen bonding (alpha or beta pleated sheet)

tertiary structure of protein

protein structure is formed when the twists and folds of the secondary structure fold again to from a larger 3D structure, stablize by side chains

quaternary structure

association of two or more polypeptide subunits.

What causes a protein to denature?

When hydrogen bonds get broken due to changes in pH, temperature, or certain chemicals

Function of DNA

stores genetic information, provides directions for it sown replication

Parts of DNA

Phosphate group, nitrogenous base (A-T, C-G), sugar (Deoxyribose)

Parts of RNA

Phosphate group, nitrogenous base (A-T, C-G), sugar (Ribose)

Eukaryote examples

plants, animals, fungi, protists

Prokaryote example

bacteria

Similarities between prokaryotes and eukaryotes

cell membrane, ribosomes, DNA, cytoplasm

Differences between eukaryotes and prokaryotes

Eukaryotes have a nucleus and prokaryotes do not. In eukaryote, DNA is in the nucleus, but in a prokaryote, DNA is in the nucleoid (not enclosed in membrane). In eukaryotes, ribosome attatcted to Rough ER, but in prokaryotes, ribosomes float freely in the cytosol.

structure of plasma membrane

double phospholipid layer. hydrophilic heads, hydrophobic tails

function of plasma membrane

to regulate what goes into and out of the cell

What easily goes into the plasma membrane?

Small, nonpolar molecules

Why are cells so small and why is it a good thing? Think of S.A. : V ratio.

smaller cells have more surface area across which to pass oxygen, nutrients and waste materials, but it has to go through less volume becaue volume doesnt increase as surface area does. Greater ratio of surface area to volume is better.

What organelles are in the endomembrane system?

nuclear envelope, endoplasmic reticulum, golgi apparatus, lysosomes, vacuoles and the plasma membrane.

nuclear envelope

layer of two membranes that surrounds the nucleus of a cell

Rough ER function

studded with ribosomes and synthesizes proteins

Smooth ER function

lipid synthesis, detoxification of poisons, drugs, and toxins, calcium storage

Golgi apparatus function

(Pancake) stack of membranes that modifies, sorts, and packages proteins from the endoplasmic reticulum. Sorts these proteins for tranpportation to lysosmes, plasma membrane, or for secretion.

Lysosomes function + how they carry out that function

Digestion of excess/worn out cell parts. recycling waste. They do this by carrying phagocytosis, engulfing small oragnisms/food particles.

Vacuoles

Stores organic compounds such as WATER, salts, proteins, and carbohydrates

Endosymbiosis theory

The theory that the eukaryotic cell evolved via the engulfing of one prokaryotic cell by another.

Differences between animal and plant cells

Plant cells have chloroplasts, cell wall, vacuole is larger than in animal cell

Animal cells have NO chloroplasts, NO cell wall, vacuole is smaller than those in plant cell

Similarities between animal and plant cells

Both have cell membrane, cytoplasm, nucleus, ribosomes, ER, mitochondria, Golgi, lysosomes, vesicles and cytoskeleton

What are plant cell walls made of? What are they good for?

cellulose, provide structure for plant

Animal cells have no cell well. What protects their organelles?

Cell membrane. Planst have it too.

ECM functions

Support, adhesion, movement, communication/regulation of behavior

What is the ECM (extracellular matrix)?

Made of glycoproteins, It connects cells, allowing them to interact, connected to the cell's interior by integrins in the cell's membrane.

Fbronectin function

Glycoprotein bound to ECM, binds integrin proteins, allows for communication between ECM and cytoskeleton