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level: Level 1

Questions and Answers List

level questions: Level 1

QuestionAnswer
flattened sacs (cisternae) and small membrane-enclosed vesiclesgolgi apparatus
The smallest particle of a substance that can exist by itself. the basic unit of an elementAtom
pure substance containing 1 kind of atomelement
2 or more different elements in a fixed ratiocompound
2 of more atoms bonded together representing the smallest fundamental unitmolecule
what are atoms composed of?protons, neutrons, and electrons
the number of protons gives theatomic number
the number of protons + neutrons + electronsatomic mass
what is atoms with different number of neutrons?isotopes
what determines how atoms will interact?electrons
locations of electrons in an atom are described byorbitals
orbital occurs in a series calledelectron shells or energy levels
the atom is stable if the outermost shell isfull
reactive atoms have _________ electrons in thier outermost shellunpaired
what holds the atoms of a molecule together?covalent bond
why do molecules form?because they can share, lose or gain electrons resulting in atoms bonded together
what is the attractive force that links atoms together to form molecules?chemical bond
what is covalent bond?atoms share one or more pairs of electrons
what is an ionic bond?when one atom is more electronegative than the other then a complete transfer of electrons occurs; electrical attrition of (+) and (-)
what is ionelectrically charged particles when atoms lose or gain electrons
cationspositive; when ions lost an electron
anionnegative; when ions gain an electron
what is hydrogen bond?attraction between the partial (-) of one molecule and the partial (+) of hydrogen end of another molecule
what is can der waals forces?attractions between nonpolar molecules that are close together
list these from the weakest to strongest: van der waals, hydrogen, covalent, and ionic bondvan der waals, hydrogen, ionic and covalent bond
Isotopes differ in the number ofmass and atomic number
What is a polar covalent bond?when one electrons are drawn to one nucleus more than to the other because one atom is more electronegative
is sharing of electrons in a covalent bond always equal?no
what is the attractive force that an atomic nucleus exerts on electronselectronegativity
what are the major classes of molecules in living organismsprotein, lipid, carbohydrates, nucleic acid
Polymer: Protein , what is the monomercombinations of 20 amino acids
Polymer: Carbohydrates, what is the monomersugar monomers (monosaccharides)
Polymer: nucleic acids, what is the monomer?4 kinds of nucleotide monomers
Polymer: lipids, what is the monomer?non-covalent forces maintain interactions between lipid monomers
functions of proteins include:antibodies, storage proteins, structural proteins, transport proteins
the terminal- SH group of cysteine can react with another cysteine side chain to form adisulfide bridge
amino acids bond together covalently in a condensation reaction bypeptide linkages
what is the primary structure of a protein and what bondis the sequence of amino acids and covalent
what is the secondary structure of protein and what bondalpha helix + beta pleated sheet and hydrogen bond
what is the alpha helix in secondary structure?right handed coil resulting from hydrogen bonding between N-H groups on one amino acid and C=O groups on another
What is the beta pleated sheet in secondar structure?two or more polypeptide chains are aligned; hydrogen form between the chains
what is the tertiary structure of protein and its bond?folding results in a macromolecule with specific 3-D shape + determined by interactions of R-groups and disulfide bridge (covalent bond), hydrogen, hydrophobic, van der waals, and ionic bond
what is the quaternary structure of proteins and what bond?results from the interaction of subunits and hydrophobic, van der waals, ionic and hydrogen bond
what results in sickle-cell disease?from a single amino acid substitution in the protein hemoglobin, a blood disorder; a change in primary structure
macromolecules are polymers built formmonomers
what is the general formula for carbohydrates?Cn(H2O)n
What is carbohydrates known for?source and transport of stored energy
one simple sugar is callmonosaccharide
two simple sugars linked by covalent bond is calldisaacharide
three to 20 monosaccharides is calloligosaccharide
hundreds or thousands of monosaccharides are callpolysaccharides: starch, glycogen and cellulose
all cells use ________ as an energy sourceglucose
monosaccharides bind together to form disaccharides in _____ reactions to form ________ linkagesdehydration and glycosidic
what include other functional groups?Oligosaccharides
storage of glucose in plantsstarch
storage of glucose in animalsglycogen
very stable, good for structural components but not storagecellulose
Cellulose if linear (T/F)T
Starch is Branched (T/F)T
Glycogen is highly branched (T/F)T
What is nonpolar hydrocarbons calllipids
what does lipid consist of ?fats, oils, phospholipids, and sterols
fats and oils storeenergy
structural role in cell membranesphospholipids
capture light energy in plantscarotenoids and chlorophylls
fats and oils are composed of ________ and ________ calledfatty acids and glycerols call triglycerides
3-OH group (an alcohol)glycerol
nonpolar hydrocarbon with a polar carboxyl groupfatty acid
carboxyl bond with hydroxyls of glycerol in anester linkage
saturated fatty acidsno double bonds between carbons, saturated with H atoms
Unsaturated fatty acidssome double bonds in carbon chain; kinks
which is solid at room temperature?saturated
what is the process called of converting unsaturated fats into saturated fats by adding hydrogenhydrogenation
what results in vegetable oils that are unsaturated fats with trans double bonds?partial hydrogenation
fatty acids are _______ they have ________ chemical properties with hydrophilic one side and hydrophobic on the other endamphipathic, opposing
2 fatty acids bound to glycerolphospholipids
why are cells so small?surface-to-volume ratio
the bigger a cell is, the less _________surface area
what are the three domains?bacteria, archaea, and eukaryota
what is the two types of cells?prokaryotic and eukaryotic
bacteria and archaea areprokaryotic
the DNA is in a membrane-enclosed compartment called thenucleus
basic features of ALL cells (both Prokaryotes and Eukaryotes) areplasma cell membrane, semifluid substance (cytosol), chromosome, and ribosomes
Prokaryotic cell differ from eukaryotes byhaving no nucleus, have DNA in an unbound region call nucleoid, no organelles
eukaryotic cells differ from prokaryotes byhaving DNA in a nucleus and membrane-bound organelles
Where are ribosomes found?rough ER and free floating cytoplasm
where are ribosomes made?nucleolus
the shape of the nucleus is maintained b thenuclear lamina (composed of proteins)
DNA is organized into discrete units calledchromosomes
the DNA and proteins chromosomes are together calledchromatin
what does the cytoskeleton do?maintains cell shape in both prokaryotes and eukaryotes and made of protein
what are the three components of cytoskeleton?microfilaments, intermediate filaments, and microtubules
microfilaments aremuscle contraction, cell division and maintaining cell shape; made from protein actin
intermediate filaments aretough protein anchoring cell structures in place like nucleus, ; forms nuclear lamina
microtublues areframework for motor proteins, form rigid internal skeleton, made from protein tubulin; flagella + cilia
undergoes reversible shape changes powered by ATP hydrolysismotor proteins
the motor protein _____ binds to a vesicle and walks it along by changing shapekinesin
which of the following is surrounded by two phospholipid bilayers?nucleus
network of interconnected membranes in the cytoplasm; has large surface areaendoplasmic reticulum (ER)
flattened sacs (cisternae) and small membrane-enclosed vesiclesgolgi apparatus
which region receives vesicles from the ER?cis region
which region does vesicles bud off from the golgi apparatus?trans region
an organelle found in the cytoplasm of most cells (especially in leukocytes and liver and kidney cells)lysosome
some types of cells can engulf another cell byphagocytosis
enzymes responsible for biosynthesis of membrane lipids would be located in what part of the cell?endoplasmic reticulum; smooth ER
this theory proposes that mitochondria and chloroplasts and other plastids arose when one cell engulfed another cellendosymbiosis theory
energy in fuel molecules is transformed to the bonds of energy-rich ATPmitochondria
mitochondria have ________ membranestwo
in mitochondria, the inner membrane folds inward to form _________cristae
the cristae of mitochondria create a large surface area for proteins involved in ________reactionscellular respiration
site of photosynthesis-- light energy is converted to the energy of chemical bondschloroplasts
how many membrane does chloroplasts havedouble membrane
stacks of thylakoidsgrana
contain chlorophyll and other pigments that harvest light energy for photosynthesisthylakoids
fluid in which grana are suspended, contains DNA and ribosomesstroma
plants and protist cells have _____, store waste products and toxic compound, provide structural supportvacuoles
peroxisomes got their name because hydrogen peroxide isused in their detoxification reactions
what is the byproduct of peroxisomes?hydrogen peroxide
what does peroxisomes oxidize?fatty acids and amino acids
which cellular structure is common to all 3 domains of life?phospholipid bilayer cell membrane