Howard University Biology 101 Final Study Guide (Ch.1 - Ch.8)

Name the groups in an experiment and the variables.

1) Experimental 2)Control 3)Independent (manipulated) 4) Dependent (measured response)

Describe the steps of the scientific method.

1) Hypothesis 2) Design an experiment 3) Conduct experiment 4) Collect Data 5) Compare results/ Research 6) Re-test to conclude if data is significant

Laws of Thermodynamics?

1) In any energy conversion, energy is neither created or destroyed 2) When energy is required, some goes to do work and energy is lost to random thermal motion

What are the three non-protein chemical partners?

1) Prosthetic fit- non-amino acid atoms permanently bound to enzymes 2) Inorganic cofactors- ions bound to enzymes 3)Coenzymes- non-protein carbon molecules required for more than one enzyme to work

Name the functions of macromolecules.

1)Defense 2) Storage 3) Energy 4)Movement 5)Support 6) Catalyst

Name the steps of protein folding.

1)Primary - A polypeptide chain has a repeating -n-c-c- chain 2)Secondary- Regular and repeating patterns begin with alpha and beta sheets 3)Tertiary - Creation of the definitive 3-D shape 4)Quaternary- multiple macromolecules come together* *Doesn't always happen

What are characteristics of living organisms?

1-Made of cells 2- Can convert molecules 3-Utilize the environment for energy 4-Have DNA to form amino acids that can be passed down through lineage 5- Can survive through homeostasis

What is a chemical bond?

A chemical bond is a force linking the two atoms together to make a molecule.

Population is?

A group of individuals of the same organism (species) that interact. They can change through evolution and natural selection.

What is entropy?

A measure of disorder in a system.

What is the fluid mosaic model?

A molecular model for the structure of biological membranes consisting of a fluid phospholipid bilayer where suspended proteins are free to move.

Chaperoning is?

A protein that aids the 3-D structure of another protein to protect it from having problems while folding and having the structure damaged.

What is the cell wall?

A semirigid structure outside the plasma membrane that is made of cellulose to give support, prevent disease, and grow as the cell expands.

What is a buffer?

A solution that can maintain a constant PH made of a weak acid and its corresponding base.

What is the extracellular matrix?

A structure that is composed of collagen, proteoglycans, and proteins for holding tissue, keeping physical properties, filtering material from other cells, orienting movement, and communicating through chemical signals.

Describe the energy coupling system.

ADP picks up energy from exergonic reactions to become ATP to donate to endergonic reactions.

What is active versus passive transport.

Active requires the use of ATP because it goes against the concentration gradient. Passive requires no energy and moves with the concentration gradient.

Name the Purines.

Adenine and Guanine (double ringed)

Electronegativity is(what does it depend on)?

An attractive force the nucleus exerts for a covalent bond. (Depends on the positive charges in the nucleus and electron distance)

What is an isotope?

Any element that differs in the amount of neutrons than is categorized as normal.

What is a Null Hypothesis.

Any observable differences that are due to the result of random differences that arise from two finite samples of the same population.

The surface-area-to-volume ratio is?

As volume increases so does the surface area, yet not at the same rate. Movement is accomplished better in a smaller cell because it has less surface area to move things.

What is the atomic numbers versus atomic mass?

Atomic numbers are based off the amount of protons, while the mass is the combination of protons and neutrons.

What are organisms made up of? (smallest to largest)

Atoms -> Molecules -> Cells (pro/euk) -> tissues -> organs -> organ systems -> organism

Metabolism?

Breaking down of components to release energy for use.

The sodium-potassium pump is?

Breaks down ATP to ADP and a free phosphate to bring two potassium into the cell and three sodium out to change the charge of the cell

Endocytosis is?

Bringing small molecules, macromolecules, or large particles into the cell through: Phagocytosis (eating) Pinocytosis (drinking)

Living Organisms are made up of?

Carbohydrates, Proteins(nucleic acids), Lipids(fatty acids)

What are the two types of energy?

Catabolic - the break down of complex molecules into simpler one (exergonic) Anabolic - links simple molecules together to create complex ones (endergonic)

What is essential to the formation and maintenance of a cell?

Cell recognition (bind to specific cells) and adhesion (connection between two cells)

What is the cell theory?

Cells are a fundamental unit of life, and all living organisms are made up of cells, these cells arise from preexisting cells.

What are Lysosomes?

Cells fro digestion of food, other cells, and other foreign material.

How does a cell move?

Cilia (small structures to propel through a fluid) and flagella ( singular or paired that pulls the cell through an environment)

What is the Endoplasmic reticulum?

Compartments that run throughout the cell from the nucleus that can have ribosomes connected to it. Rough - transports ribosomes which can be tagged to go to specific locations Smooth - responsible for chemical modification of toxins, where lipids are synthesized and calcium is stored.

Name the inhibitor types.

Competitive - competes with natural substrate to attach to active site Uncompetitive - binds to enzyme-substrate complex to prevent the release of products Noncompetitive - attaches to area away from active site to change the enzymes shape

What are the two types of experiments?

Controlled (manipulates one or more factors) Comparative ( compares unmanipulated data from multiple sources)

Name the Pyrimadines.

Cytosine and Thymine (single ringed)

What is the central Dogma?

DNA is transcribed to RNA which is translated into a Protein/polypeptide.

Describe DNA.

Double stranded deoxyribonucleic acid which is a macromolecule passed from generation to generation that hold our genes. (A,G,C,T)

What is a chloroplast?

Green chlorophyll which is the site of photosynthesis, and has thylakoids (stacks of granums).

What are complex ions?

Groups of covalently bonded atoms that carry an electrical charge. Once stability has been reached no more electrons are gained or lost.

Proteins can be denatured by?

Higher temperatures (heat), alterations of PH (acid), high concentrations of polar substances and non-polar structures.

What are ribosomes?

Hold ribosomal RNA and are connected or free from the endoplasmic reticulum or within the

What is Homotypic versus Heterotypic?

Homo is the binding of cells in tissues while hetero is two different cells bind.

The three states a cell can acquire are?

Hypertonic - more solute than water which causes it to shrivel Hypotonic - more water than solute which creates a bloat Isotonic - equal parts of solution and water

What is an Isomer and the two types?

Isomers are atoms that have the same formula but can be arranged in different structures. The two types are structural ( atoms are joined different, there is a double bond of carbon), and optical (carbon has four different attachments which can cause two different structures).

What is Hydrolysis?

It breaks down polymers into monomers by the addition of water.

Describe a Lipid.

Lipids are hydrocarbons that are insoluble in water due to their non-covalent forces. They are fats such as oil, phospholipids, carotenoids (light absorbing pigments in plants), steroids (relay chemical messages), vitamins (small molecules), and waxes (saturated fatty acids).

What is the Golgi apparatus?

Made of a cisternae and vesicles meant to receive proteins from the ER for modification and storage.

Describe a nucleotide.

Made up of a nitrogenous base of A,D,C,T, a pentose 5 carbon sugar and a phosphate backbone. They are connected by phosphodiester bonds to move from 5' to 3'.

Exocytosis is?

Materials packaged in vesicles are secreted from it by fusing to the membrane.

What is matter made up of?

Matter is made of atoms which consist of neutrons (0), electrons (-), and protons (+).

What is Mass.

Measure of the quantity of matter (daltons).

What are the different types of filaments in a cell?

Microfilaments - helps stabilize and determine shape Intermediate - help anchor in place and resist tension Microtubules - long, hallow, unbranched cylinders to create the framework of a cell

What are monomers versus polymers?

Monomers are small molecules and polymers are covalently bonded monomers.

Eukaryotes are?

Multi-cellular organisms derived from prokaryotes with externals and internal membranes as well as a nucleus and mitochondria.

Anions are?

Negatively charged ions.

Describe hydrogen bonds.

Negatively charged oxygen with positively charged hydrogens. They are very weak bonds that can be broken apart easily, unless there are many of them. The two types are hydrophilic (loves water and forms strong reactions) and hydrophobic (hates water and forms weak reactions).

What is cellulose?

Organic compound that is a polysaccharide of glucose made up of beta glycosidic linkage.

What is a Condensation reaction?

Otherwise known as dehydration synthesis, it forms covalent bonds by removing water.

What is the Plasma Membrane?

Outer protective surface of every cell that is selectively permeable, thus allowing specific molecules to get in . It allows for homeostasis to occur, communication through cells adjacent to it and can utilize binding proteins.

Describe PH and its scale.

PH is the measure of hydrogen concentrations within substances. It goes from 1 being acidic (release H+) to 7 as neutral then 14 being basic (accepts H+). This can affect the shape of specific molecules unless given a buffer.

Name the two types of membranes.

Peripheral membrane - proteins are not embedded in the lips bilayer but have polar charged regions to interact with exposed polar heads Integral membrane - sit partially in the phospholipid bilayer and have hydrophilic and phobic regions that goes all the way through the bilayer.

List the steps of grouping of organisms

Population -> Community -> Ecosystem -> Biosphere

Cations are?

Positively charged ions.

Describe Qualitative versus Quantitive data.

Qualitative - identifies a substance in a chemical reaction Quantitive - measures the concentration and amounts of a substance

Whats are Mitochondria?

Receive molecules that are degraded and harvest the energy to produce ATP which goes through cellular respiration. Made up of cristae (folds for ATP generation) and a matrix (contains ribosomes, DNA, and enzymes for energy conservation).

Describe RNA.

Ribonucleic acid which is single stranded and tells the information obtained from DNA to create a coded protein which forms genes. (A,G,C,U)

Specificity of a protein is dependent upon?

Shape (must be 3-D) and Chemistry ( have R-group)

What is specific heat and heat of vaporization?

Specific heat is heat energy required to raise 1g. of a substances temperature. Vaporization is the heat required to change something to a gaseous form.

What is a catalyst?

Substances that speed up reactions but cannot make a reaction occur that wouldn't normally do so. To reach a certain state there must be enough energy.

What does a cytoskeleton do?

Supports the cell.

Cohesion is?

The capacity of H20 to resist coming apart due to surface tension (attractive forces on water).

What is energy?

The capacity to do work and change. Reactions can either release or require energy.

Prokaryotes are?

The first known organisms that are uni-cellular with a single outer membrane and no nucleus such as bacteria.

Describe a valence shell.

The outermost shell which holds the eight valence electrons and determines the chemical behavior of the atom.

What is the nucleus?

The site of DNA and its replication where the gene for transcription is either on/off. Hold the nucleolus where ribosomes are assembled and is surrounded by a nuclear envelope.

What is the metabolism?

The sum total of all the chemical reactions occurring in a biological system through the use of energy which is either potential (stored) or kinetic (energy to do work).

The endosymbiosis theory is?

The theory that eukaryotic cell evolved via the engulfing of one prokaryote to another.

Describe an ionic bond.

The transfer of unequally shared electrons, they are generally weak and not completely stable.

What is the structure of an amino acid?

There is a center carbon with a hydrogen group, carboxyl, R-group and amino group.

Describe a Carbohydrate.

They are giant molecules made of monosaccharides and polysaccharides with the general form of C(x)H(2x)O(x) and are meant to store energy or give energy. Ex- Glucose (mono), Starch (Poly)

Describe proteins and their function.

They are made up of 20 amino acids and are meant to perform a specific function which a gene encodes. They can be an enzyme, help with cell structure and stability, respond to defense, create and receive cell signals, transport items through membranes, store amino acids, and regulate gene expression.

What is a nucleic acid?

They are polymers specialized fro storage, transmission and genetic information.

What do Vacuoles do?

They are used for storage of toxins and waste, structure of turgor pressure, reproduction of pigment, and digestion of enzymes that hydrolyze proteins.

What do nutrients do?

They give energy to organisms for biochemical reactions, help with mechanical work (movement), go through synthesis to build structures, and can create electrical work (neurons synapsis)

Name which makes up an enzyme and what they have to do in order to work.

They must orient their substrate, induce stress to stretch the substrate to make it unstable and add chemical groups.

When do chemical reactions occur?

They occur when moving atoms collide with large enough energy to change or bind to each other. The go from reactants to products.

How did life start?

Through the process of water.

What are the three types of cellular junctions?

Tight - prevents movement of substrates between cells that can restrict the migration of a cell within a tissue Desmosome - holds a cell together, yet materials can move through the extracellular matrix Gap - channels hat go between membrane pores in adjacent cells allowing for the transfer of material

Describe a covalent, non polar, and polar covalent bond?

Two atoms sharing an electron, they are strong bonds and generally stable. Non-polar covalent are two atoms that are close in electronegativity with equal shares on pull. Polar covalent is when one nucleus pulls an electron more than the other.

Types of Active transport cells are?

Uniporter - single substance in one direction Symporter - two substances in one direction Antiporter - two substances in opposite directions

What is a radioisotope?

Unstable molecule that gives off energy such as beta, gamma, and alpha which can create radioactive decay to transform an atom.