Chapters 1-3 Flashcards
Biology
the scientific study of life
Properties of life
- order
- reproduction
- growth and development
- energy processing
- regulation
- response to the environment
- evolutionary adaptation.
Cell
structural and functional unit of life
Taxonomists
name species and classify them into broader groups.
Domain groups
Bacteria, Archaea, and Eukarya
Bacteria and Archaea domains
Contain organisms with simple cells
Domain Eukarya
various protists and the kingdoms Fungi, Plantae, and Animalia
Emergent properties
result from the specific arrangement and interactions among component parts.
Structural levels of biology
Biosphere -> ecosystem -> community -> population -> organism -> organs and organ system -> tissue -> cell -> organelle -> molecule
Science
is a way of knowing—an approach to understanding the natural world.
Scientific approach
involves observations, hypotheses, predictions, tests of hypotheses via experiments or additional observations, and analysis of data.
Scientific theory
is broad in scope and supported by a large body of evidence.
Independent variable
The factor that is manipulated in experiment
Dependent variable
The measure used to judge the outcome of the experiment
Controlled experiment
compares an experimental group with a control group.
Endeavor of science
influenced by three spheres:
- exploration and discovery
- analysis and feedback from the scientific community
- societal benefits and outcomes.
Goal of technology
apply scientific knowledge for some specific purpose.
Goal of science
understand natural phenomena.
Natural selection
Unequal reproductive success leads to evolution of adaptations in populations
Artificial selection
Selective breeding of plants and animals.
DNA functions
responsible for heredity and for programming the activities of a cell by providing the blueprint for proteins.
Energy flows…
through an ecosystem in one direction
- entering as sunlight
- converted to chemical energy by producers
- passed on to consumers
- exiting as heat.
What are ecosystems characterized by?
the cycling of matter
- from the atmosphere and soil,
- through producers, consumers, and decomposers,
- then back to the environment.
Systems biology
Where scientists attempt to model the behavior of biological systems by analyzing the interactions among their parts
Mitosis
Cell division that results in two daughter cells that have the same number of chromosomes.
Apotosis
When cells kill themselves to prevent over mitotic division
Data
Recorded observations
Qualitative Data
Recorded descriptions
Quantitative data
Frequency and duration of specific behaviors. Frequently numerical and measurements.
Hypothesis
Proposed explanation for a set of observations, and it leads to predictions that it can be tested by making additional observations or by performing experiments
Experiment
A scientific test
Evolution
Scientific explanation for unity and diversity.
How might a chemical compound in the air harm coral reefs?
When carbon dioxide (CO2) dissolves in water, it reacts with water to form an acid, which then makes the water more acidic.
How many elements are essential for human life?
- Four make up 96% of weight of most living organismsm.
Compound
substance consisting of two or more different elements in a fixed ratio.
Why are some trace elements required?
to prevent disease. Examples: iodine, fluoride
Atom
the smallest unit of matter that still retains the properties of an element.
Mass number
the sum of the number of protons and neutrons in the nucleus. Atomic mass approximately equal to this.
Isotopes
Element that have the same number of protons but different numbers of neutrons.
Why are radioactive isotopes helpful?
Useful as tracers for monitoring the fate of atoms in living organisms.
Where are electrons located?
in different electron shells, each with a characteristic distance from the nucleus.
Chemical bonds
an attraction that results from an atom whose outer electron shell is not full interacts with other atoms and share, gain, or lose electrons,
Nonpolar covalent bond
electrons are shared equally.
Polar covalent bond
electrons are pulled closer to the more electronegative atom.
Ion
atom or molecule with an electrical charge resulting from gain or loss of one or more electrons.
Ionic bond
When attraction holds together two ions with opposite charges.
Hydrogen bond
The hydrogen atoms of a water molecule are attached to oxygen by polar covalent bonds. Is a polar molecule
Chemical reaction
The composition of matter is changed as bonds are broken and formed to convert reactants to products.
Cohesion
The tendency of molecules of the same kind to stick together
Adhesion
The tendency of two kinds of molecules to stick together
Surface tension
measure of how difficult it is to break the surface of a liquid.
Evaporative cooling
When a substance evaporates, the surface of the liquid that remains behind cools down
Solution
a liquid consisting of a uniform mixture of two or more substances.
Buffer
minimizes changes in pH.
Ocean acidification
When CO2 dissolved in seawater lowers the pH of the ocean
Matter
Anything that occupies space and has mass.
Radioactive isotope
An isotope where the nucleus decays spontaneously, giving off particles and energy.
Covalent bond
Atoms do not transfer electrons but share electrons between them.
Electronegativity
Measure of an atom’s attraction for shared electrons.
Thermal energy
Energy associated with the random movement of atoms and molecules.
Heat
Thermal energy in transfer from a warmer to a cooler body.
Temperature
Measures the intensity of heat.
Solute
Substance that is dissolved in a liquid
Solvent
The dissolving agent in a solution
Acid
substance that donates hydrogen ions to solutions
Base
Substance that reduces the hydrogen concentration of a solution.
4 carbon-containing molecules in humans
Lipids, proteins, carbohydrates, and nucleic acids
CHNOPS - most important inorganic materials
carbon, hydrogen, nitrogen, oxygen, phosphorus, sulfur
Exothermic
release heat
endothermic
absorb heat
Isomers
Compounds with the same molecular formula but different structural arrangement.
Hydrocarbons
Molecules composed of only carbon and hydrogen.
What does an organic compound’s properties depend on
size and shape of its carbon backbone and atoms attached to that skeleton
Hydrophilic functional groups
Water-loving. give organic molecules specific chemical properties. First five of the six chemical groups - hydroxyl, carbonyl, carboxyl, amino group, and phosphate group.
Monomers
The building blocks of polymers
dehydration reactions
How monomers are linked together to form polymers. Reaction removes a molecules of water as two molecules become bonded together. Reaction mediated by enzymes.
monosaccharides
Sugar monomers. simple sugars. Main fuel for cellular work.
disaccharide
Formed when two monosaccharides (monomers) bond in a dehydration reaction. Sucrose most common (fructose + glucose)
Cellulose
Tough walls that enclose plant walls. Polymer of glucose
Chitin
Polysaccharide. component of insect exoskeletons and fungal cell walls. a protein
Lipids
Fats. are diverse hydrophobic compounds composed largely of carbon and hydrogen. Do not mix well with water.
Fats (triglycerides)
Large lipid made from two kinds of smaller molecules: glycerol and fatty acids.
Unsaturated fatty acids
fatty acids that contain one or more double bonds. Plant oils
Saturated fatty acids
Fats with the maximum number of hydrogen atoms. Animal fats.
Phospholipids
Components of cell membrane. Part of phospholipid bilayer.
Steroids
include cholesterol and some hormones.
Cholesterol
common component in animal cell membranes and is also the precursor for making other steroids, including sex hormones.
Anabolic steroids
synthetic variants of the male hormone testosterone that are abused by some athletes with serious consequences.
Protein functions
- enzymes,
- transport proteins embedded in cell membranes,
- defensive proteins, such as antibodies,
- signal proteins such as many hormones,
- receptor proteins,
- contractile proteins found within muscle cells,
- structural proteins such as collagen, and
- storage proteins.
Denaturation
a protein unravels, loses its specific shape, and loses its function.
Proteins
are made from amino acids linked by peptide bonds. end -in
Peptide bond
When amino acid monomers link together in a dehydration reaction, joining the carboxyl group of one amino acid to the amino group of the next amino acid
polypeptide
a chain of amino acids
Protein four levels of structure
- primary: sequence of amino acids in its polypeptide chain.
- secondary: coiling or folding of the chain, stabilized by hydrogen bonds. Alpha helix OR beta pleated sheet.
- tertiary: result from interactions among R groups. 1 alpha helix added with 1 beta pleated sheet
- quaternary: Proteins made of more than one polypeptide. 2 alpha helix + 2 beta pleated sheets
Nucleotides
monomers that make up nucleic acids. are composed of a sugar, a phosphate group, and a nitrogenous base.
Organic compounds
Carbon-based molecules. Usually contain hydrogen bonds in addition to carbon.
Hydroxyl group
Made of a hydrogen atom bonded to an oxygen atom. i.e. ethanol
Carbonyl group
Carbon atom linked by double bond to an oxygen atom. Simple sugars
Carboxyl group
Carbon double-bonded to an oxygen atom and a hydroxyl group. Act as an acid by contributing H+ to a solution.
Carboxylic acids
Compounds with carboxyl groups
Animo group
Nitrogen atom bonded to two hydrogen atoms. Act as base by picking up H+ atom from solution and becoming ionized.
Amines
Organic compounds with an amino group.
Amino acid
Building blocks of proteins. Contain an amino and a carboxyl group. Monomers that contain an amino group, carboxyl group, an H atom, and an R group with central carbon atom
Phosphate group
Phosphorus atom bonded to four oxygen atoms.
Organic phsophates
Compounds with phosphate groups. Often involved in energy transfers
Methyl group
Carbon bonded to three hydrogen atoms. DNA
Macromolecules
Carbohydrates, proteins, and nucleic acids. Huge molecules made from polymers
Hydrolysis
Reverse of dehydration reaction. Polymers are broken apart by adding water
Enzymes
Specialized macromolecules that speed up chemical reactions in cells. End in -ase
Polysaccharides
Macromolecules, polymers of hundreds to thousands of monosaccharides linked together by dehydration reactions. Function as storage molecules or as structural compounds - starch, glycogen, cellulose
Starch
Storage polysaccharide in plants. Made from glucose monomers
Glycogen
Storage polysaccharide in animals.
Gene
Amino acid sequence of a polypeptide that is programmed by a discrete unit of inheritance
DNA
Deoxyribonucleic acid. Nucleotides adenine, thymine, cytosine, guanine.
Nucleic Acids
DNA and RNA
DNA transfer
DNA -> transcription -> mRNA message -> translation -> sequence of amino acids (primary protein)
Structural isomer
Different covalent partnerships between atoms
Geometric isomer
Cross. Vary in arrangement of atoms around a double bond
Enantiomer isomer
Molecules which are mirror images of each other
Lactose
Galactose and glucose
Maltose
Glucose and glucose
