Chapter 3: Structure and Function of Molecules Flashcards
what four molecules are composed of carbon compounds?
proteins, DNA, carbohydrates, lipids
framework of biological molecules consists primarily of carbon bonded to…
C. H, O, N, P. S
carbon forms…
4 covalent bonds
hydrocarbons are
molecules consisting only of carbon and hydrogen
what allows carbon to bond with different atoms?
the electron configuration
carbon frequently bonds with
H, O, N
hydrocarbons that undergo reactions can release?
larger amounts of energy
what is an isomer?
compounds with the same molecular formula but different structures and properties
What are the three types of isomers?
- structural isomers
- cis-trans isomers
- enantiomers
structural isomers
have different covalent arrangements of their atoms
cis-tans isomers
have the same covalent bonds but different spatial arrangements
cis isomer: x’s are on the same side
trans isomer: x’s are on the opposite side
enantiomers are
isomers that are mirror images of each other
What are the seven functional groups that are most important in the chemistry of life?
- hydroxyl group
- carbonyl group
- carboxyl group
- amino group
- sulfhydryl group
- phosphate group
- methyl group
Functional groups…
transform the carbon chain
what are the functional groups of carbohydrates?
-OH (hydroxyl)
C=O (carbonyl)
What are the functional groups of amino acids?
- COOH (carboxyl)
- NH2 (amino group)
Sulfhydryl (-SH)
stabilizes protein structure and is critical in protein folding
What is the functional group of phospholipids and DNA
-OPO 3^2- (phosphate group)
how is the functional group phosphate unique?
it forma 5 bonds
The Methyl group (-CH3) is important for
gene expression
the most important type of phosphate is
ATP adenosine triphosphate
Macromolecules are…
large complex molecules
what are the four biological molecules?
- carbohydrates
- lipids
- proteins
- nucleic acids
A polymer is…
a long molecule consisting of many similar building blocks
A monomer is…
repeating units that serve as building
What macromolecules are polymers?
- carbohydrates
- proteins
- nucleic acids
enzymes are…
specialized macromolecules that speed up chemical reactions
enzymes ____ or ____ _____ polymers.
make; break down
What is dehydration synthesis?
two monomers bond together trough loss of a water molecule
What is hydrolysis?
polymers broken down to monomers by water
ALL enzymes are
proteins
carbohydrates serve as
fuel and building material
carbohydrates include
sugars and the polymers of sugars
carbohydrate monomers are…
monosaccharides
carbohydrates are good at
storing energy
carbohydrates polymer are…
polysaccharides
ALL carbohydrates have a 1:2:1 ratio with
H, O, C
monosaccharides are classified by…
- the location of the carbonyl groups (C=O)
- the number of carbons
- the arrangement of the hydroxyl groups (-OH)
What is the difference between structural and stereo isomers?
structural isomers are identified by the location of the bonded carbonyl group. Stereo isomers are identified by the orientation of the hydroxyl group.
Disaccharides are
2 monosaccharides linked together by dehydration synthesis
monosaccharides are
the simplest sugars
glyosidic linkage
when carbon of a monosaccharide in a disaccharide is bonded to another monosaccharide through an oxygen atom
polysaccharides are
long chains of monosaccharides
polysaccharides are linked through
dehydration synthesis
polysaccharide’s shape and function is determined by
the sugar monomers and the glyosidic linkages
structural support of polysaccharides are…
cellulose, and chitin
cellulose is a
major component of the plant cell wall
What is the storage of polysaccharides in plants and animals?
plants: starch
animals: glycogen
fats are constructed from two smaller molecules which are..
- glyerol
2. fatty acid
Glycerol is a
3-carbon alcohol with a hydroxyl group attached to each carbon
a fatty acid consists of
a carboxyl group attached to a long carbon skeleton
fats are linked through
ester linkages
phospholipids are composed of
- glycerol
- 2 fatty acids (nonpolar tails)
- a phosphate group (polar head)
carbohydrates are bonded through…
glycosidic linkages
functions of proteins include
- speeding up chemical reactions
- defense, storage, transport, cellular communication, movement, regulation, structural support
monomers of proteins are
set of 20 amino acids
polymers of proteins are
polypeptides
polypeptides are…
unbranched chains of amino acids
amino acids are…
molecules with amino, carboxyl, and R groups
hydrophobic side chains (R groups) consist of
carbohydrates (C & H)
hydrophilic side chains (R groups) consist of
oxygen (polar)
R groups that are electrically charged are considered to be
hydrophilic
amino acids are linked by dehydration synthesis to form covalent ____ ____.
peptide bonds
each polypeptide has a carboxyl and amino end which are called/
C-terminus
N-terminus
specific activity of proteins result from…
the unique 3-D shape
The four levels of protein structure are…
- primary
- secondary
- tertiary
- quaternary
the primary structure is
a linear sequence of amino acids
ex: letters in a long word
the secondary structure results from
hydrogen bonds between amino acid monomer R-groups in the polypeptide chain
the two secondary structures are
- alpha helix
2. beta pleated sheet
the tertiary structure is formed by
the overall shape of a polypeptide, these result from interactions between R groups of secondary structures
What are disulfide bridges?
strong covalent bonds that reinforce the protein’s structure
quaternary structure happens when…
a complete protein consists of multiple folded polypeptides
protein shape is affected by
temperature and changes in pH
Denaturation is…
the loss of a protein’s natural shape
nucleic acids…
store, transport, and help express hereditary information
A gene is
a unit of heritance consisting of DNA which encodes the amino acid sequence of a polypeptide
the polymer and monomer of genes are…
polymer: nucleic acid
monomer: nucleotides
What are the two types of nucleic acids?
- deoxyribonucleic acid (DNA)
2. ribonucleic acid (RNA)
DNA directs the synthesis of
messenger RNA
Gene expression is..
the process where DNA instructions synthesizes proteins
Ribosomes are the only machines that know how to read mRNA, what is this process called?
translation
nucleotides are composed of
- nitrogen containing base
- pentose sugar
- one or more phosphate groups
What causes the difference in the sugars of DNA and RNA
- RNA is composed of OH
- DNA is composed of H
What are the nitrogenous bases of DNA and RNA?
DNA- ATGC
RNA- AUCG
nucleotides are joined by dehydration synthesis to form a
phosphodiester linkage
What creates the “rails” of DNA?
a sugar-phosphate backbone
What forms the steps of the ladder in DNA
nitrogenous bases held together with hydrogen bonds
Antiparallel is the
arrangement of backbones running in opposite directions
Complementary base pairing is…
bonding with corresponding pair of nitrogenous base (A+T)
RNA is _____ _____ and can form _____ structures.
single stranded
variable
ATP is a
nucleotide
