what are the basic building blocks of all matter? A. electrons B. protons C. atoms D. molecules
C. atoms
which feature of water explains why water has high surfface tension? A. water deffuses into cells B. waters resistance to temp changes C. water is a polar molecular D. water expands when it freezes
C. water is a polar molecular
which of the following describes an isotope of the commonly occurring oxygen atom which has 8 electroons 8 protons and 8 neutrons A. 8 electrons 8 protons and 9 neutrons B. 7 electrons 8 protons 8 neutrons C. 8 electrons 7 protons and 8 neutrons D. 7 elec
A. 8 electrons 8 protons and 9 neutrons
which of the following will form a solution? A. sand and water B. oil and water C. salt and water D. salt and sand
C. salt and water
which of the following applies to a water molecular? A. water is a nonpolar molecular B. the atoms in water are bonded by ionic bonds C. the weak bond between two water molecurs is a covalent bond D. water molecures have a negativaly charged end and posit
D. water molecures have a negativaly charged end and positively charged end
which of the following carbohydrates is a plysaccharide? A. glucose B. fructose C. sucrose D. starch
D. starch
which of the following pair is unrelated? A. sugar - carbohydrerates B. fat- lipid C. amino acid- protein D. starch - nucleic acid
D. starch - nucleic acid
an acid is any substance the forms _____ in water A. hydroxide ions B. oxigen ions C. hydrogen ions D. sodium ions
C. hydrogen ions
which of these is not made up of proteins? A. hair B. enzymes C. fingernails D. cellulose
D. cellulose
which of the followin is not a smaller subunit of a nucleotide? A. phosphare B. nitrogen C. ribose sugar D. glycerol
D. glycerol
an enzyme _____ chemical reactions.
speeds
a calcium atom has 20 protons and _____ electrons
20
a _____ bond involves sharing of electrons.
covalent
the first energy level of an atom holds _____ electrons the second energy level holds 8 electrons
2
in a water molecule each ____ atom shares one electron with the single ____ atom
hydrogen, oxygen
a substance fits into an area of an enzyme called the ____
active site
hydrogen chlorine and sodium are examples of ______
elements
long chains of amino acids connected to each other by a _____ bond form a ______
peptide, protein
difgusion is the process in which molecules move from a ______ concentration to a _____ concentration
high, low
the positively charged ______ atoms of one water molecule attract the negativey charged ______ atom of another water molecule to form a hydrogen bond
hydrogen , oxygen