Biology 101: Intro to Biology Studying for Biology 101

Polymers

These long chains of molecules contain smaller units, called monomers. They can be made of monomers of the same type or different types, and occur both artificially and in nature.

Starch

A carbohydrate in the form of complex sugars that humans can digest, though it may take a while. It provides a significant amount of energy for humans.

Trisaccharide

This large sugar would contain three smaller monosaccharides.

Heterotroph

This term refers to organisms that must eat other organisms in order to gain sustenance. All living creatures excepting plants and some algae are this type of organism.

Triglycerides

A kind of lipid that contains a glycerol and three fatty acids. Examples include saturated and unsaturated fats.

Unsaturated Solution

This term refers to any solution that can hold more of a particular solute.

Saturated Solution

This occurs when a solvent can no longer dissolve any more of the solute. If you add sugar to water and mix, you will create this kind of solution once the sugar begins to sit on the bottom.

Valence Electrons

These electrons stay in the outermost shell of their atom. They differ from other electrons in that they directly interact with different atoms.

Osmosis

A process that involves the movement of solvent molecules. This passage takes place across the semi-permeable membrane of a cell.

Organic Chemistry

In the past, this branch of chemistry focused on studying molecules that were found in things that were alive or had once been alive. Now it focuses on any molecule containing carbon.

Hypertonic Solution

A kind of solution that is defined against another solution. This solution will have a higher concentration of a specific solution than another solution.

Innermost Electron Shell of an Atom

This level of the electron shell contains the electrons closest to the nucleus.

Chemical Bond

A type of bond that occurs between at least two atoms that are oppositely charged.

Hypotonic Solution

Solutions of this sort contain concentrations of a solute that are lower than the concentrations found in other solutions.

Electron Cloud

Electrons exist in this area inside of an atom.

Lipids

These biological molecules are not water soluble and come in two categories, glycerol and steroids. As a steroid, this molecule can carry chemical messages.

Electron Shell

A scientific term that refers to the area that surrounds the nucleus of an atom. This is where electrons are generally located.

Protein

A kind of biological molecule formed from amino acids. These molecules use peptide bonds to stay together. Examples can include insulin, transcription factors and hemoglobin.

Cellulose

This is also known as dietary fiber and it is basically the structural material we find within plants. Humans cannot digest this carbohydrate.

Atoms

The basic unit of matter that makes up everything around us. This unit contains three smaller particles that it can be divided into: protons, electrons and neutrons.

Monosaccharide

This term refers to sugars that exist as single units.

Atomic Number

A number determined by the amount of protons contained within the nucleus of an atom.

Proton

A positively charged subatomic particle.

Neutron

These subatomic particles have a neutral charge and are generally found in an atom's atomic nucleus.

Enzymes

This important kind of protein is responsible for facilitating chemical reactions in our bodies.

Supersaturated Solution

A solution that holds more solute than should be held by a saturated solution.

Electron

This subatomic particle has a negative charge and very little mass.

Lactic Acid Fermentation

This type of respiration does not require oxygen. This process ends up converting pyruvate into lactic acid.

Chloroplasts

a plant organelle where photosynthesis occurs

Fermentation

This biological process occurs during anaerobic cellular respiration. Cells can only go through glycolysis in this process and so create only 2 ATP for each glucose molecule involved.

Lactase

This enzyme helps your body break down the lactose found in dairy products.

Glucose

Cellular respiration uses this sugar as its primary fuel source.

Photolysis

This process splits water with the use of light energy. It occurs during photosynthesis and results in the production of oxygen.

Photosynthesis

Plants use this process in order to change carbon dioxide, solar energy, and water into oxygen and glucose.

The Calvin Cycle

This part of photosynthesis is also referred to as dark reactions. It occurs when plants carry out photosynthesis without using any light energy.

Point of Saturation

This refers to the point in an enzymatic reaction where adding further substrate won't continue to increase the rate of reaction. The reaction will plateau because it can no longer expand.

Carbon Fixation

This is the process that takes place when inorganic carbon is changed into organic carbon. Plants such as algae carry out this process during the Calvin cycle.

Aerobic Respiration

This type of cellular respiration can only occur with oxygen. Anaerobic cellular respiration, or respiration without oxygen, can also occur but is less effective.

Cellular Respiration

This biological process involves the conversion of food into energy at the cellular level.

Cellular Respiration Equation

Organic compounds (proteins, lipids, carbohydrates) + oxygen leads to carbon dioxide + energy + water

Things produced due to oxygen reactions in cellular respiration

• Water

• Energy

• Carbon dioxide

Electron Carriers

molecules responsible for accepted and transporting electrons as they move during cellular respiration

Organic compounds found in food

• Carbohydrates

• Proteins

• Lipids

Inhibitor Molecules

These molecules disrupt the activities of enzymes.

Steps in Cellular Respiration

• Glycolysis

• The citric acid cycle

• The electron transport chain

Components of Adenosine Triphosphate (ATP)

• Adenine base

• Ribose sugar

• Three phosphates

Pepsin

an enzyme that works well in acidic environments, such as the human stomach

Coenzymes

These cofactors typically come from vitamins. They are organic molecules that work to help improve the functions of enzymes and can bind to them.

Activator Molecules

This kind of molecule may help an enzyme begin a process, continue working or increase the reaction rate by regulating the activity of the enzyme.

Pigments

Plants use these in order to absorb light to carry out the process of photosynthesis. Chlorophyll is an example of this.

Alcoholic Fermentation

This is one kind of anaerobic respiration. During this process, pyruvate is changed into alcohol.

Selectively Permeable Membrane

A barrier that allows some materials to pass through it but not all

Phospholipid

A component of a cell membrane composed of a phosphate group, which is hydrophilic and polar, and a lipid, which is hydrophobic and nonpolar

Cell Membrane

A membrane that separates the intracellular and extracellular environments using a phospholipid bilayer

Phagocytosis

The process by which a cell folds its cell membrane around large particles or other cells, creating a vesicle, and then 'eats' them; for example, a white blood cell devouring a bacterium

Pinocytosis

Process by which a cell's membrane surrounds liquids and small dissolved molecules and brings them into a vesicle, where the cell 'drinks them; e.g., cells by capillaries 'drink' blood

Vesicle

A circular bud made of membrane that is formed during the process of endocytosis when a cell surrounds an object with its cell membrane

Lysosome

A structure within a cell responsible for breaking down food, foreign objects, and old cellular components found within the cell using digestive enzymes for reuse or recycling by the cell

Types of Membrane Proteins Used in Active Transport

• Uniport: moves a substance in one direction
  

• Antiport: moves two substances in opposite directions
  

• Symport: moves two substances in the same direction

Concentration Gradient

The gradual difference in the concentration of a solute between two areas

Active Transport

A type of transport across cell membranes that requires the use of energy due to ions or molecules moving against their concentration gradient, from areas of low to high solute concentration

Endocytosis

• The process of bringing large particles into a cell through the folding inward of its cell membrane

• Three types include phagocytosis, pinocytosis, and receptor-mediated endocytosis

Cholesterol

Hydrophobic material that floats in phospholipid bilayers; helps preserve the fluidity of membranes and works as a barrier against unwanted molecules

Diffusion

A type of passive transport in which solutes move along their concentration gradient, from an area of high concentration to an area of low concentration

Passive transport

A type of transport across cell membranes that does not involve the use of energy

Hypotonic Solution

A solution that contains less solutes inside a cell membrane compared to outside the membrane

Cytoplasm

The space inside a cell that holds the different parts that work together in order for a cell to function

Sodium-Potassium Pump

In nerve cells; an antiport that moves sodium ions outside the cell and potassium ions into the cell to maintain a concentration gradient (more sodium outside the cell, more potassium inside)

Ribosome

• Small structure found in the cytoplasm and on the endoplasmic reticulum

• Made up of a large and a small subunit

• The site of translation (protein building)

Structure of the Endoplasmic Reticulum (ER)

• Found by the nucleus and arranged as tubes of membrane

• Inside is known as the lumen

• Two types: rough ER (contains ribosomes) and smooth ER (builds steroids and lipids)

Bacteriophage

A type of virus that can only use bacteria as a host

Eukaryotic Cell

• Composed of a nucleus (to store the cell's DNA) as well as other membrane-bound organelles, such as the mitochondria

• Organisms with these types of cells are called eukaryotes

Chloroplast

A cell organelle only found in plant cells where photosynthesis occurs

Made up of thylakoids (stacked together into grana) found within a liquid chamber called the stroma

Cell Wall

• Found on the outside of plant cells

• Serves as a protective barrier

• Controls the transport of materials

• Made primarily of the sugar cellulose

Prokaryotic Cell

• Does not have a nucleus or other organelles with membranes

• Classified as either bacteria or archaea

• Organisms with these types of cells are called prokaryotes

Nuclear Envelope

A structure made up of an inner and outer (double) membrane that surrounds and protects the nucleus

Cytoskeleton

The 'skeleton' of the cell

Important for holding the shape of a cell, allowing for movement, and holding organelles in place

Made up of microtubules, intermediate filaments, and microfilaments

Endomembrane System

• Made up of the endoplasmic reticulum and the Golgi apparatus

• Acts like the post office of the cell by 'packing,' 'addressing,' and 'delivering' substances around and out of the cell

Mitochondria

Organelles surrounded by outer and inner membranes that are responsible for the creation of energy from food through the process of cellular respiration

Transcription

• The process of making an RNA copy out of a stretch of DNA

• Takes place in the nucleus

RNA Polymerase

This enzyme uses either strand of a DNA template to join nucleotides together, producing strands of RNA. It starts working by binding to a promoter region found on a molecule of DNA.

Transcription

The process of using a DNA blueprint to make an RNA copy. Genetic information is copied from DNA to RNA when this occurs.

The Three Steps of Translation

Initiation, elongation, and termination

Alternative Splicing

A principle that explains how single genes are able to code for multiple proteins.

DNA: Complementary Base Pairings

These occur due to the way nitrogenous bases connect. Purines hook to pyrimidines, which means that cytosine pairs with guanine and adenine pairs with thymine.

Relationship Between DNA and the Three Types of RNA

A short stretch of DNA is used as a template to make an mRNA copy, which then joins up with a ribosome (which contains rRNA). Then tRNA brings in amino acids to make a protein.

Central Dogma

Describes how heritable information in a cell is expressed

A DNA recipe is transcribed into mRNA, which is then translated (or 'cooked') into a protein made up of amino acids.

Okazaki Fragments

Small stretches of DNA made by DNA polymerase during the process of DNA replication. They are joined together by DNA ligase and used during discontinuous replication of the lagging strand.

RNA: Nitrogenous Bases

• Guanine

• Cytosine

• Adenine

• Uracil

Complementary Base Pairing in DNA

• Cytosine and guanine always base pair together, forming three hydrogen bonds

• Adenine and thymine always base pair together, forming two hydrogen bonds

Ribosomal RNA (rRNA)

A type of RNA found within a ribosome for structural purposes

DNA Polymerase

• A large enzyme that adds nucleotides to a growing daughter DNA strand by using the parent strand as a template.

• Requires an RNA primer to start, and reads a strand in a 3' to 5' direction.

Messenger RNA (mRNA)

The type of RNA that is read by a ribosome and serves as a template for the production of a protein. It is formed during the central dogma's first step.

Lagging Strand

• One of the two parent strands of DNA that runs 5' to 3'

• Replication is discontinuous on this strand and requires the use of Okazaki fragments.

Ribonucleic Acid (RNA)

Single-stranded nucleic acid made up of a sugar (ribose), a phosphate, and nitrogenous bases (adenine, cytosine, guanine, and uracil). It is less stable than another nucleic acid, DNA.

RNA Primase

An enzyme that synthesizes a primer that allows for the start of replication.

Deoxyribonucleic Acid (DNA)

Double-stranded helix of nucleotides made up of a sugar (deoxyribose), a phosphate, and one of four nitrogenous bases (adenine, cytosine, guanine, and thymine)

Anticodon

Three consecutive bases within a tRNA molecule that complementary base pair with a codon on an mRNA

Semi-Conservatice Model

The correct model that describes how DNA replication occurs. States that each DNA strand serves as a template for a new strand so that each new double helix has one new and one old DNA strand

Replication Forks

• Two found in every replication bubble

• Allow for replication to take place in both directions away from the replication bubble