Midterm #1 Vocabulary Flashcards
Cell
The smallest structural and functional unit of an organism
Data
Recorded observations
Quantitative : numerical measurements → graphs, tables
Qualitative : recorded descriptions
Dependent Variable
Variable whose value is measured during an experiment or other test to see whether it’s influenced by changes in another variable (independent variable)
in the termite experiment: did the termite follow the line?
Deoxyribonucleic Acid (DNA)
A nucleic acid molecule, usually a double-stranded helix, in which each polynucleotide strand consists of nucleotide monomers with a deoxyribose sugar and the nitrogenous bases adenine (A), guanine (G), thymine (T), and cytosine (C); capable of being replicated and determining the inherited structure of a cell’s proteins
Eukaryotic Cell
Type of cell with a membrane-enclosed nucleus and membrane-enclosed organelles.
Organisms with eukaryotic cells are called Eukaryotes.
Evolution
Descent with modification; the idea that living species are descendants of ancestral species that were different from the present-day ones; also defined more narrowly as the change in genetic composition of a population from generation to generation.
Experiment
A scientific test, carried out under controlled conditions, involving manipulation of one or more factors in a system in order to see the effects of those changes
Gene
A discrete unit of hereditary information consisting of a specific nucleotide sequence in DNA (or RNA, in some viruses).
Independent Variable
Variable whose value is manipulated or changed during and experiment or other test to reveal possible effects on another variable (the dependent variable).
What are the levels of biological organization?
“BEC POOT COM”
- Biosphere
- Ecosystems
- Communities
- Populations
- Organisms
- Organs and Organ Systems
- Tissues
- Cells
- Organelles
- Molecules
Natural Selection
Process in which individuals that have certain inherited traits tend to survive and reproduce at higher rates than other individuals because of those traits.
Prokaryotic Cell
Type of cell lacking a membrane-enclosed nucleus and membrane-enclosed organelles.
DO NOT HAVE GOLGI APPARATUSES!
Organisms with prokaryotic cells are called Prokaryotes.
What are the steps in the scientific method?
- Observation
- Question
- Hypothesis
- Prediction
- Test the prediction
- Results
Atom
The smallest unit of matter that still retains the properties of an element
Proton
Positively charged subatomic particle
• Number of protons is the same as the atomic number
Electron
Negatively charged subatomic particle
Neutron
Electrically neutral subatomic particle
• The number of neutrons + the number of protons (the atomic number) = the mass number
Molecule
Atoms bonded together
Ion
An atom or group of atoms that has gained or lost one or more electrons, thus acquiring a charge
Valence Electron
An electron in the outermost electron shell
Electronegativity
The attraction of a particular atom for the electrons of a covalent bond
Nonpolar Covalent Bond
Type of covalent bond in which electrons are shared equally between 2 atoms of similar electronegativity
Polar Covalent Bond
Covalent bond between atoms that differ in electronegativity. The shared electrons are pulled closer to the more negative atom, making it slightly negative and the other atom slightly positive
Partial Charge
,
Hydrogen Bond
Type of weak chemical bond that’s formed when the slightly positive hydrogen atom of a polar covalent bond in one molecule is attracted to the slightly negative atom of a polar covalent bond in another molecule or in another region of the same molecule.
Solute
The substance that is dissolved
Solvent
Dissolving agent of a solution
Hydrophilic
Having an affinity for water
Hydrophobic
Having no affinity for water; tending to coalesce and form droplets in water
Organic Molecule
Molecule containing carbon (since carbon determines if something is organic)
Monomer
The repeating units that serve as the building blocks of a polymer
Polymer
A long molecule consisting of many similar or identical building blocks linked by covalent bonds
Functional Group
A specific configuration of atoms commonly attached to the carbon skeletons of organic molecules and involved in chemical reactions.
• There are 7 functional groups
Hydroxyl Group
(-OH) or (HO-)
• chemically reactive
• hydrophilic
→ polar due to electronegative oxygen
→ forms hydrogen bonds with water, helping dissolve compounds
→ compound name : alcohol (specific name usually ends in -ol)
Carboxyl Group
(-COOH)
• chemically reactive
• hydrophilic
→ acts as an acid (can donate H+) because the covalent bond between oxygen and hydrogen is so polar
→ compound name : carboxylic acid, or organic acid
Amino Group
(-NH2) • chemically reactive • hydrophilic → acts as a base; can pick up an H+ from the surrounding solution (water, in living organisms) → compound name : amine
Phosphate Group
(-OPO3 2-) • chemically reactive • hydrophilic → contributes negative charge (1- when inside a chain of phosphates; 2- when at the end). When attached, congers on a molecule the ability to react with water, releasing energy. → compound name : organic phosphate
Protein
A biologically functional molecule made up of one or more polypeptides (polymer of amino acids), each folded and coiled into a specific 3D structure
Amino Acid
An organic molecule with both an amino group (-NH2) and a carboxyl group (-COOH).
→ At the center is an asymmetric carbon atom (the alpha carbon), and its 4 different partners are an amino group, a carboxyl group, a hydrogen atom, and a variable group R (side chain)
Side Chain
Variable group attached to the asymmetric carbon in an amino acid. The physical and chemical properties of the side chain (R group) determines the unique characteristics of a particular amino acid, thus affecting its functional role in a polypeptide.
Peptide
A compound consisting of 2 or more amino acids linked in a chain. Bound by peptide bonds.
Carbohydrate
A sugar (monosaccharide) or one of its dimers (disaccharides) or polymers (polysaccharides)
Sugar
A monosaccharide
Monosaccharide
The simplest carbohydrate, active alone or serving s a monomer for disaccharides and polysaccharides. Also called simple sugars, monosaccharides have molecular formulas that are generally some multiple of CH2O.
→ most common monosaccharide is glucose (C6H12O6)
→ most names end in -ose
→ location of carbonyl group decided if its an aldose (glucose) or ketose (fructose)
→ trademark = carbonyl group (CO) and multiple hydroxyl groups (OH)
Polysaccharide
Polymers with a few hundred to a few thousand monosaccharides joined by glycosidic linkages
Nucleic Acid
Polymer made of monomers called nucleotides
Ribonucleic Acid (RNA)
Type of nucleic acid consisting of a polynucleotide made up of nucleotide monomers with a ribose sugar and the nitrogenous bases
• Usually single stranded
• Functions in protein synthesis, gene regulation, and as the genome of some viruses
Nucleotide
The building block of a nucleic acid, consisting of a 5-carbon sugar covalently bonded to a nitrogenous base and one or more phosphate groups
Lipid
Any of a group of large biological molecules, including fats, phospholipids, and steroids, that mix poorly, if at all, with water
Triglyceride (AKA Fat or Triglycerol)
A lipid consisting of 3 fatty acids linked to one glycerol molecule.
Steroid
Lipid characterized by a carbon skeleton consisting of 4 fused rings
Phospholipid
Lipid made up of glycerol joined to 2 fatty acids and a phosphate group. The hydrocarbon chains of the fatty acids act as nonpolar, hydrophobic tails, while the rest of the molecule acts as a polar, hydrophilic head.
→ form bilayers that function as biological membrane that shields their hydrophobic portions from water.
Amphipathic
Containing both a hydrophilic and a hydrophobic region
Hydrolysis
Chemical reaction that breaks bonds between 2 molecules by the addition of water; disassembles polymers into monomers
Cell Wall
1
Chloroplast
Found in plants and algae. Site of photosynthesis.
Chromatin
The complex of RNA and proteins making up chromosomes
Cytoplasm
Contents of the cell bounded by the plasma membrane; in Eukaryotes, it is the portion exclusive of the nucleus
Cytoskeleton
Network of fibers extending throughout the cytoplasm. Gives mechanical support to the cell and maintains its shape.
Works with motor proteins and plasma membrane molecules to move entire cells, and make “feet” for cell parts to “walk”
Golgi Apparatus
The warehouse for receiving, sorting, shipping, and even some manufacturing.
→ cisternae: flattened membranous sacs, separating its internal space from the cytosol
→ cis face: receiving department
→ trans face: shipping department
Lysosomes
Membranous sac of hydrolytic enzymes that many eukaryotic cells use to digest (hydrolyze) macromolecules. Highly acidic inside.
→ carry out intercellular digestion via phagocytosis and autophagy
Mitochondria
Sites of cellular respiration (metabolic process using oxygen to create ATP by extracting energy from sugars, fats…)
THE MITOCHONDRIA IS THE POWER HOUSE OF THE CELL!!!
Nucleus
Organelle of the eukaryotic cell that contains the genetic material in the form of chromosomes (which are made up of chromatin).
Synthesizes mRNA
Nucleolus
Specialized structure in the nucleus consisting of chromosomal regions containing ribosomal RNA (rRNA) genes and ribosomal proteins imported from the cytoplasm. Site of rRNA synthesis and ribosomal subunit assembly.
Nuclear Envelope
Double membrane that surrounds the nucleus, perforated with pores that regulate traffic with the cytoplasm. The outer membrane is continuous with the endoplasmic reticulum.
Plasma Membrane
Membrane at the boundary of every cell that acts as a selective barrier, regulating the cell’s chemical composition
Ribosome
Complex made of ribosomal rRNA and protein that carries out protein synthesis. Has no membrane, therefore is not an organelle.
→ free ribosomes = suspended in cytosol and makes proteins for cytosol
→ bound ribosomes = attached to the outside of the endoplasmic reticulum or nuclear envelope. Makes proteins for insertion into membranes.
Rough Endoplasmic Reticulum
Endoplasmic reticulum with ribosomes attached to it that create proteins, which are later secreted by cells.
ex: the pancreas secreting the protein insulin
Smooth Endoplasmic Reticulum
Endoplasmic reticulum that functions in diverse metabolic processes that vary with cell type, including lipid synthesis, metabolism of carbs, detoxification of drugs and poisons, and storage of calcium ions.
Vacuole
Large vesicle derived from the endoplasmic reticulum and Golgi apparatus.
→ food vacuole: formed by phagocytosis
→ contractile vacuole: pumps excess water out of the cell (usually in unicellular organisms)
→ central vacuole: in mature plant cells when smaller vacuoles coalesce. Filled with sap, the main repository of inorganic ions, and plays a role in the growth of plant cells.
Vesicles
Tiny sacs made of membrane
Dynein
Motor protein
Kinesin
Motor protein
Myosin
Motor protein
Tubulin
Protein that makes up microtubules
Microtubule
Hollow rods constructed from tubulin protein. Shape and support the cell, makes tracks for cell parts to move, and guide vesicles from the endoplasmic reticulum to the Golgi apparatus and to the plasma membrane.
Actin
1
Light Microscopy
Uses visible light to magnify a specimen through glass lenses that refract (bend) the lights
Electron Micrscopy
Focuses a beam of electrons through the specimen/onto its surface
Virus
An infectious particle consisting of little more than genes (nucleic acids) packaged in a protein coat.
• Can be called a DNA or an RNA virus depending of the kind of nucleic acid(s) that make up its genome
Host
1
Genome
1
Capsid
Protein shell enclosing the viral genome
• built from capsomeres
Viral Envelope
Membranous envelope surrounding the capsid of some viruses, containing host cell phospholipids and membrane proteins. The viral envelope can help the virus infect its host.
Glycoprotein (for viruses)
w
Cell Lysis
When a cell swells (like in a hypotonic solution) and then bursts (or when a virus enters the lytic cycle and, after reproduction, causes the cell to burst and release the virus and its next generation)
Retrovirus
RNA animal virus with reverse transcriptase enzyme that transcribes an RNA template into DNA
ex: HIV/AIDS
Reverse Transcriptase
Enzyme used by the HIV virus to transcribe an RNA template into DNA (backwards- usually DNA makes RNA)
Viroid
Circular RNA molecules that are only a few hundred nucleotides long. Infects plants and causes errors in regulatory systems.
Prion
Infectious protein that causes degenerative brain diseases in various animal species. Has a 10 year incubation period and is virtually indestructible.
Phospholipid
Lipid made up of glycerol joined to 2 fatty acids and a phosphate group. The hydrocarbon chains of the fatty acids act as nonpolar, hydrophobic tails, while the rest of the molecule acts as a polar, hydrophilic head. Form bilayers that function as biological membranes that shield their hydrophobic portions from water.
Saturated Fatty Acid
A fatty acid in which all carbons in the hydrocarbon tail are connected by single bonds, thus maximizing the number of hydrogen atoms that are attached to the carbon skeleton.
→ think of butter; less fluid, more solid
Unsaturated Fatty Acid
A fatty acid that has one or more double bonds between carbons in the hydrocarbon tail. Such bonding reduces the number of hydrogen atoms attached to the carbon skeleton.
→ think of oils; more fluid
Membrane
1
Fluid Mosaic
1
Integral Proteins
Proteins penetrating the hydrophobic interior of the lipid bilayer
Peripheral Proteins
Protein that is an appendage, loosely bound to the surface of the membrane, often to exposed parts of integral proteins
Selective Permeability
Allowing some substances to cross a membrane easier than other substances
Gradient
3
Diffusion
The movement of particles of any substance so that they spread out into the available space
Passive Transport
When energy isn’t used to move a substance through the membrane (ex: diffusion)
Active Transport
When a cell uses energy to pump a solute across a membrane against its gradient.
This enables the cell to maintain internal concentrations of small solutes that differ from concentrations in its environment.
Channel Protein
Transport protein that functions by having a hydrophilic channel that certain molecules or atomic ions use as a tunnel through the membrane
Carrier Protein
Transport protein that holds onto its passengers and changes shape in a way that shuttles them across the membrane
Pump
1
Osmosis
The diffusion of free water across a selectively permeable membrane
Water will move from a low solute concentration to a high solute concentration to balance out the concentrations.
Hypertonic
The solution has MORE nonpenetrating solutes, therefore the cell will lose water, shrivel, and most likely die
Hypotonic
The solution has LESS nonpenetrating solutes, therefore water will enter the cell faster than it leaves, causing the cell to swell and eventually lyse
Receptor
5
Endocytosis
When cell takes in molecules and particulate matter by forming new vesicles from the plasma membrane (looks like reverse exocytosis)
→ phagocytosis: cell engulfs particle
→ pinocytosis: cell “gulps” droplets of extracellular fluid into vesicles
→ receptor-mediated endocytosis: specialized type of pinocytosis
Exocytosis
When cells secrete certain molecules by the fusion of vesicles with the plasma membrane
Energy
The capacity to cause change
Free Energy
The portion of a system’s energy that can perform work when temperature and pressure are uniform throughout the system
Potential Energy
Energy that isn’t kinetic (relative motion of objects); energy that matter possesses because of its location or structure
Entropy
Measure of disorder, randomness
Reactants
Left side of the equation; what will react to form the products
Products
Right side of the equation; what is formed by the reactants
Exergonic
Releases energy
Endergonic
Consumes energy
Spontaneous
“energetically favorable”
If a reaction is considered spontaneous, it does not require energy and the process by itself leads to an increase in entropy.
Adenosine Triphosphate (ATP)
Sugar ribose with adenine and 3 phosphate groups. Mediates most energy coupling in cells; immediate source of energy that powers cellular work; bonds broken by hydrolysis.
Phosphorylation
0
Energy Coupling
The use of an exergonic process to drive an endergonic one.
Enzyme
Molecule that acts as a catalyst (speeds up the reaction without being consumed by it).
Catalyst
Chemical agent that speeds up a reaction without being consumed by the reaction.
Activation Energy
The initial investment of energy for starting a reaction.
Often supplied by heat in the form of thermal energy.
Transition State
Unstable condition due to molecules absorbing enough energy for bonds to break (once activation energy is reached)
Active Site
Region of enzyme molecule that binds to the substrate
Competitive Inhibitor
Enzyme inhibitor that resembles the normal substrate and competes for entry into the active site
Noncompetitive Inhibitor
Enzyme inhibitor that binds to another part of the enzyme which changes the enzyme’s shape, which in turn makes the enzyme less effective
Allosteric Effect
Any case in which a protein’s function at one site is affected by the binding of a regulatory molecule to a separate site.
Conformational Change
1
Feedback Regulation
1
Coenzyme
Cofactor that is an organic molecule
Cofactor
Nonprotein helper for catalytic activity
Metabolic Pathway
Route in which a specific molecule is altered in a series of defined steps and ends up as a certain product. Each step is catalyzed by a specific enzyme.
