Module 2 Biochemistry of the cell Flashcards
emphasized that for life to
exist at all , the environment must first be suitable and that leads to water
Richard Henderson
Water has four emergent properties which are stated below:
- Cohesion and Adhesion of Water Molecules
- Moderation of Temperature by Water.
- Evaporative Cooling of Water
- Water as the Solvent of Life
Water molecules stay close to each other as a result of ___ and these bonds that hold the water together, is a phenomenon called ____.
contributes to the
transport of water and dissolved nutrients against gravity in plants
hydrogen bonding
cohesion
the clinging of one substance to another
This ____ of water to cell walls by hydrogen bonds helps counter the downward pull of gravity.
adhesion
Water moderates air temperature by
absorbing heat from air that is warmer and releasing the
stored heat to air that is cooler
This property of water also helps warm the air when it is nighttime and tends to stabilize the ocean temperature
heat must be absorbed in order to break hydrogen bonds
heat is released when hydrogen bonds formed
contributes to the stability of temperature in lakes and ponds
also provides a mechanism that prevents terrestrial organisms from overheating
helps keep the tissue in the leaves from becoming too warm in the sunlight
Evaporative cooling of water
The solvent is then involved in the dissolving of ions which contributes to processes happening in the body such as the formation of the ___
hydration shell
Biomolecules (4)
Nucleic Acids
Proteins
Lipids
Carbohydrates
macromolecules that exist as polymers
They store, transmit, and help express hereditary
information.
Nucleic acids
A nucleotide is composed of three parts:
a nitrogenous base
a five-carbon sugar
one or more phosphate groups
In a polynucleotide, each ___ has only one ____.
The portion of the nucleotide without any phosphate groups is called a ____.
monomer
phosphate group
nucleoside
two families of nitrogenous bases:
has one six-membered ring of carbon and nitrogen atoms.
larger, with a six-membered ring fused to a five-membered ring.
Pyrimidine
Purines
Pyrimidine (3)
cytosine, thymine, and uracil
Purines (2)
adenine, and guanine
found in both DNA and RNA (3)
____ is only found in DNA and ____ only in RNA
Adenine
Guanine
Cytosine
Thymine
Uracil
Pairings
Adenine =
Guanine =
Thymine, Uracil
Cytosine
The two ____ run in arrangement called “antiparallel”
sugar phosphate backbones
a biologically functional molecule that consists of one or more polypeptides (polymers of amino acids)
protein
Shapes of protein (2)
Globular Proteins
Fibrous Proteins
Folding of proteins are done by ____
chaperonins
when proteins are transferred from an aqueous environment to a ____, it unravels and loses its native shape by a process called denaturation.
non-polar solvent
It is a linked series of amino acids with a unique sequence
Structure from inherited genetic information.
Primary Structure
This is collectively referred to as ____ which are the result of hydrogen bonds between the repeating constituents of the polypeptide backbone
coils and folds
Secondary structure:
a delicate coil held together by hydrogen bonding between every fourth amino acid.
two or more strands of the polyopeptide chain lying side by side (called b strands) are connected by hydrogen bonds between parts of the two parallel polypeptide backbones.
a- helix
b pleated sheet
It is the overall shape of a polypeptide resulting from interactions between the side chains (R groups) of the various amino acids.
Tertiary structure:
Tertiary structure interactions:
caused by the exclusion of nonpolar substances by the water molecules
Hydrophobic interaction
Tertiary structure interactions:
Hydrogen and ionic bonds:
Hydrogen bonds are between ___ and ionic bonds are between ___
polar side chains
positively and negatively charged side chains
Tertiary structure interactions:
These further reinforce the shape of a protein. ___ bridges are formed when two ____ have ____on their side
chains which are brought closer together by the folding of protein.
Disulfide
cysteine monomers
sulfhydryl groups (-SH)
It is the overall protein structure that results from the
aggregation of these polypeptide subunits, the a and b subunits.
Quaternary structure
Proteins function as: (8)
enzymes
storage of amino acids
coordinator of an organism’s activities
motor proteins for movement
protection against disease
transport of substances
response of cell to a chemical stimuli
support
Proteins function as:
enzymes , selectively accelerating chemical reactions, such as ___ on hydrolyzing bonds inn food molecules.
storage of amino acids, such as the ____, protein of egg white serve as storage of amino acid for the developing embryo.
coordinator of an organism’s activities such as ____regulating blood sugar concentration.
motor proteins for movement such as ____ for the contraction of muscles.
protection against disease such as ____ inactivating bacteria and viruses.
transport of substances, such as ____ transporting oxygen.
response of cell to a chemical stimuli
support such as ____ providing a fibrous framework in connective
tissues.
digestive enzymes
ovalbumin
insulin
actin and myosin
antibodies
hemoglobin
collagen and elastin
one class of biomolecules that does not include true polymers, and they are generally not big enough to be considered as macromolecules.
major function is energy storage
also cushion such vital organs as the kidneys
Lipids
three types of lipids
fats
phospholipids
steroids.
A fat is constructed from two kinds of smaller molecules:
glycerol and
fatty acids
___ is an alcohol; each of its three carbons bear a hydroxyl group
____ has a long carbon skeleton, having a carbon at one end which is a part of the carboxyl group.
Glycerol
A fatty acid
Fatty acids are hydrophobic(away from water) due to the nonpolar ____.
C-H bonds
: These are formed if there are no double bonds between carbon atoms composing a chain, then as many hydrogen atoms as possible are bonded to the carbon skeleton.
They lack double bonds, and their flexibility allows the fat molecules to pack together tightly.
Saturated fatty acid
It has one or more double bonds , with one fewer hydrogen atom on each double-bonded carbon. Its double bonds are cis which has kinks to prevent the molecules from packing together closely enough to solidify at room temperature
Unsaturated fatty acid
Cells could not exist without ____, since they are essential on making up the cell membranes
function as a boundary between the cell and its
external environment
phospholipids
A phospholipid is similar to a fat molecule but
has only two fatty acids attached to glycerol rather than three
Parts of phospholipids (2)
Hydrocarbon tails (hydrophobic)
Hydrophilic head
(affinity of water)
When phospholipids are added to water, they self-assemble into double-layered structures called ___
bilayers
These are lipids characterized by a carbon skeleton consisting of four fused rings
Steroids
a crucial molecule in animals since it is a component of animal cell membranes and is also the precursor from which other steroids are synthesized, such as the sex hormones
Cholesterol
Carbohydrates include both sugars and polymers of sugars.
Simplest forms of Carbohydrates
Consists of two monosaccharides joined by a covalent bond
Polymers composed of many sugar building blocks
monosaccharides, or simple sugars
Disaccharides
polysaccharides
Monosaccharides are simple sugars which generally have formulas that are some
multiple of the unit ____
the most common monosaccharide ____, is of
central importance in the chemistry of life
Monosaccharides, are major nutrients for cells
CH2O
Glucose (C6H12O6)
Disaccharides consist of two monosaccharides joined by a glycosidic linkage, a covalent bond formed by a ____.
Common types of disaccharides in food (2)
Plants also transports cards from leaves to roots as ___
dehydration reaction
Maltose, Lactose
Sucrose
Polysaccharides are macromolecules, polymers with a few thousand monosaccharides joined by linkages.
Some polysaccharides serve a storage material, ____ as needed to provide sugar for cells, or even used as a building material.
Plants store ___, a
polymer of glucose monomers, within the _____. enabling the plant to stockpile surplus glucose, and represents as a stored energy.
While animals store____mainly in liver and this is released when the demand for
sugar is high, serving as a fuel.
organisms build strong materials from it such as the ____ which is the major
component of the tough walls that enclose plant cells
Another structural
polysaccharide is ____ where it is used by arthropods for their exoskeleton (hard case
protecting the soft parts of the body).
hydrolyzed
starch
plastids
glycogen
cellulose
chitin
