Unit #1 Flashcards
What plays a central role in the coding of biological information?
The sequence of base pairs in a DNA molecule
How can you make a DNA model look more like RNA?
Change the deoxyribose to ribose by adding -OH groups
(Ribose sugars have -OH linked to them, deoxyribose do not)
What process adds a monosaccharide to an already existing polysaccharide?
Dehydration synthesis (opposite is hydrolysis.) An enzyme removes the hydrogen from the monosaccharide and the hydroxide from the polysaccharide which creates a bond between the two & also creating a water molecule
What’s dehydration synthesis?
When 2 monomers bond through the loss of a water molecule
What’s hydrolysis?
When a molecule’s bond is broken due to adding a molecule of water (opposite of dehydration synthesis)
Monosaccharide
A sugar that can’t be hydrolyzed/simplified into simpler sugars (ex. glucose, fructose, galactose, deoxyribose, ribose, etc)
Have molecular formulas that are usually multiples of CH2O
Glucose (C6H12O6) is the most common monosaccharide
Polysaccharide
3 or more monosaccharides linked together by a glycosidic linkage
Monomer
Atoms/small molecules that bond together to form polymers or more complex structures. They’re the building blocks. For example, the main four types of monomers consist of simple sugars, fatty acids (… sort of), amino acids and nucleotides
Polymer
Monomers bonded by a covalent bond, making polymers
Disaccharide
When two monosaccharides are joined by a glycosidic linkage
Glycosidic linkage
A link between two monosaccharides (an ester bond)
Is a glycosidic linkage covalent? Are monomers and monosaccharides, etc the same?
Yes to both. A glycosidic linkage is a type of covalent bond. Monomers are building blocks and a monosaccharides is one so yes. Polymers also is the same thing as polyssachrides, just a vaguer term
What’s cellulose?
Cellulose is a polyssacharide/polymer that consists of 3000 or more glucose monomers
If cattle were to lose the ability to maintain a colony of microorganisms (that produce enzyme B) in their digestive tract, what would occur?
The cattle would not longer be able to use cellulose as a main source of glucose because without enzyme B, cellulose wouldn’t be able to get digested
What breaks down carbs?
Enzymes break down carbs
How does the structure of ice benefit the organisms that live beneath the water?
The water molecules in ice are farther apart than those in liquid water, so when the ice floats, it maintains the warmer, denser water at the lake bottom
How is water pulled up through the xylem (inside the stem), to the leaves of the plant?
it’s pulled up through the xylem due to the hydrogen bonding between water molecules and cohesion
There are two plants, one is phosphorus sufficient and the other one is phosphorus starved. What is most likely the reason for the difference in leaf growth?
The growth was limited due to nucleic acids and lipids not being produced since phosphorus is used to produce both
What’s a peptide?
Short string of amino acids (polymer) which was formed due to dehydration synthesis and joined together by a covalent bond
What’s a polypeptide?
A continuous branch of amino acids made up of peptide bonds
What’s a dipeptide?
Two amino acid molecules linked by a peptide bond
What’s the difference between an ionic bond, a covalent bond and a hydrogen bond?
Ionic bonds: Atoms being held together by charge
Covalent: Pairs of electrons are shared by atoms
Hydrogen: Partial positive hydrogen is attracted/gets electrons taken away by a partial negative atom
Do any amino acids have phosphorus in them?
None at all. Nucleotides (monomers of nucleic acids) are the ones who do
What’s a key difference among the 20 amino acids that are used to make proteins?
10 out of 20 amino acids are hydrophobic due to non-polar R groups
What are the nucleotides both in DNA and RNA?
DNA; Adenine (A), Thymine (T). Guanine (G), and Cytosine (C)
RNA: Adenine (A), Uracil (U), Guanine (G), and Cytosine (C)
What are the building blocks for each macromolecule?
Lipids; Fatty acids and glycerol
Proteins; Amino acids
Nucleic acids; Nucleotides
Carbohydrates; Monosaccharides/Simple sugars
Hydrophillic
Likes water
Hydrophobic
Dislikes water
Polar
Has a charge
Non-polar
No charge
Hydrocarbon
A compound consisting of ONLY hydrogen and carbon atoms
How’s water able to move upward from the roots of a plant, through its xylem in the stem, and out to the leaves?
Water and xylem are both polar. The water molecules have the ability to form hydrogen bonds with each other and the xylem’s walls
How does amino acid result in decreased catalytic activity by a mutated enzyme?
The substitution of the enzyme alters the secondary and tertiary structure of the enzyme so the mutated enzyme folds into a different shape than the normal one
What’s substitution?
A type of mutation of which a nucleotide is replaced by another different one
Why does bile salt cause sulfur powder to sink?
Bile salt interferes with hydrogen bonds which reduces the surface tension. That allows the sulfur powder to sink
An amino acid is found in a region of a polypeptide that folds away from water. What part of the amino acid most likely contributes to the hydrophobic behavior of this region of the polypeptide?
The methyl group because it makes the region of the polypeptide more hydrophobic due to the group being non-polar. Also one of the functional groups that differentiate the 20 amino acids found in proteins
What results in the formation of a triplex DNA structure?
Nucleotides don’t form between complementary strands of DNA meanwhile hydrogen bonds form between the bases on complementary strands of DNA
Which one contains phosphorus;
DNA or simple carbohydrates?
DNA, simple carbohydrates usually do not
Why do guanine-cytosine pairs denature at higher temperatures?
The only bonds that form between base pairs are hydrogen bonds. Guanine-cytosine has three hydrogen bonds meanwhile adenine-thymine have two. This means that guanine-cytosine denature at a higher temperature because of the three hydrogen bonds
Denature
The breaking up or unfolding of a protein. A denatured protein is biologically inactive
Non-polar is…
Hydrophobic. Same thing applies with polar being hydrophilic
What results in hydrogen bonding in water molecules?
Polar covalent bonds (atoms that have a charge to which are bonded and share electrons)
Is water a polar or non-polar molecule?
Polar. The overall charge is unevenly distributed due to the oxygen
What are the four properties of water that life depend on?
Cohesive behavior, the ability for water to moderate its own temperature, expansion upon freezing (the water molecules being more organized and expanded in ice which gives it less density than liquid water), and versatility as a solvent
Cohesion
When water molecules are held together by their hydrogen bonds
Adhesion
An attraction between different substances
Surface tension
A measure of how hard it is to break the surface of a liquid. Cohesion between water molecules make up surface tension in water
Oxygen in a water molecule…
Holds onto electrons for longer, giving it a partial negative charge (known as electronegativity.) The oxygen acts as a negative charge
Hydrogen in a water molecule…
Acts a positive charge because it has protons for a while
Polar covalent
Unequal sharing of electrons
Particles
Atoms, neutrons, electrons, protons, ions, etc
Ion
An atom or group of atoms that either have a positive or negative charge (+ is cation, - is anion.) They’re formed by the loss or gain of electrons. They contain an uneven number of protons and electrons
More protons = positive charge (cation)
More electrons = negative charge (anion)O
Proton
A sub-atomic particle that has a positive charge
Neutron
A sub-atomic particle that has a neutral charge
Electron
A sub-atomic particle that has a negative charge
Kinetic energy
Energy an object has due to motion
Thermal energy
Kinetic energy that’s involved with random motion of molecules or atoms
Temperature
A measure of energy that shows the average kinetic energy of molecules that are in a body of matter (ex. water)
