Biochemistry unit flashcards
biochemistry
The study of the chemical processes occurring in living matter.
Matter:
anything that takes up space and has mass
Element
a pure substance that cannot be broken down to other substances via chemical reactions (any substance on the periodic table)
Compound
a substance consisting of two or more elements combined in a fixed ratio.
What are some examples of compounds
(CO, CO2, H2O)
Molecule:
a substance in which two or more atoms join together chemically. (
are all compounds molecules?
yes
are all molecules compounds?
no
What are elments composed of ?
atoms
What are atoms composed of?
protons, neutrons, and electrons
Atomic Number:
signifies the number of protons or the number of electrons in a neutral atom
Mass number:
signifies the sum of protons and neutrons
Isotope
ne of several atomic forms of an element, each containing a different number of neutrons and thus differing in atomic mass.
Ion
an atom that has gained or lost electron(s)
Anion
indicate a - charged atom which has lost (an) electron(s)
break down the word anion
an- meaning to go up
cation
indicate a + charged atom which has lost (an) electron(s)
break down the word cation
cat- meaning to go down
polar covalent bond
Unequal sharing of electrons in valence shells
-different charges
What is an example of a molecule with polar covalent bonds?
H2O
Can polar covalent bonds exist between two molecules of the same atomic mass?
no, only non polar covalent bonds can, because they would have the same charge
Non-Polar Covalent
Equal sharing of electrons in valence shells
Ionic Bonds
-gain or loss of electrons from valence shells
-Causes an imbalance in electrical charge
-As a result of this exchange, ions are formed
What charges do non-polar covalent bonds result in?
NO CHARGES, remains neutral
Why does water have unique physical and chemical structure?
Oxygen shares e- unevenly with hydrogen due to its higher electronegativity, causing many polar covalent bonds to form.
in H20, which atoms are cations and which are anions?
the oxygen end of the molecule appears negatively charged while the hydrogen end appears positive
Hydrogen bonding
a weak intermolecular attraction between a water molecule and another water molecule or another polar molecule
Why does hydrogen bonding occur?
because of the polar covalent bonds between hydrogen and oxygen. This is because since oxygen is positively charged, and hydrogen is negatively charged, the hydrogen atoms are attracted to oxygen atoms on other water molecules.
Why does water exhibit both cohesive and adhesive properties?
polar covalent bonding
Why does water become less dense and expand as it freezes?
hydrogen bonding
Adhesion
-Water molecules stick to other charged particles
What water properties does adhesion enable?
-universal solvent
- capillary action
What are the substances that water and cannot dissolve?
Water dissolves polar solutes.
-Water cannot easily dissolve non-polar solutes
Hydrophobic
Non-polar substances
Hydrophilic
Polar and Ionic substances
Capillary Action
Water adheres to sides of tubes and other charged surfaces, rising against force of gravity
Cohesion
Water molecules stick to themselves
What water properties does cohesion enable?
High Heat of Vaporization
High Surface Tension
Why does water have a high heat of vaporization?
Because water molecules cohere, more energy is required to break them apart
What substances have a low heat of vaporization?
Non-polar substances have less cohesion and hence lower heats of vaporization
Specific Heat Capacity
The amount of heat that must be absorbed or lost for 1g of water to change its temperature by 1°C.
High Surface Tension
s water interfaces with air at the surface, water molecules cohere, creating a less penetrable surface
Surfactants
substances that break surface tension
What are the main roles of water in the biosphere?
-Organisms depend on the cohesion and adhesion of water molecules
-Water moderates temperatures on earth
-Water is the only substance to exist in all three common states of matter(solid, liquid, and gas) on Earth
-Oceans and lakes don’t freeze solid because ice floats
-Water is the solvent of life
What are the efects of acids and bases on ecosystems?
-carbon dioxide sensors in carotid artery measure blood pH and tell brain when to signal lungs to breathe
-Absorption and digestion require specific pH
-pH may prohibit parasitic infections
-Changes in pH may alter or destroy enzymes
What are organic compounds?
compounds containing hydrogen and carbon
Ex: Carbohydrates, Lipids, Proteins, Nucleic Acids
What are inorganic compounds?
compounds not containing carbon and hydrogen atoms
What are the main elements of biomolecules?
-C: Carbon
-H: Hydrogen
-N:Nitrogen
-O:Oxygen
-P: Phosphorus
-S:Sulfur
What are carbohydrates and what are they composed of?
Includes sugars and their polymers
Composed of C, H, and O
Hydrogen and oxygen atoms are always in a 2:1 ratio
Why are carbohydrates important to organisms?
Serve as fuel for physiological processes and a carbon source for growth and development
monosaccharides
the simplest carbohydrate: single sugar
Most form ring structures
General formula: CH2O
Polysaccharides
Polymers formed via dehydration synthesis and glycosidic linkage formation of hundreds to thousands of carbohydrate monomers
Starch
A storage polysaccharide in plants composed entirely of glucose monomers (α glycosidic linkage)
Glycogen
A storage polysaccharide in animals composed entirely of glucose monomers
Cellulose+are they digestible & why?
storage polysaccharide in plants composed entirely of glucose monomers
β-glycosidic linkages make it indigestible by humans and many other consumers
What are lipids and what is their composition?
A group of compounds including fats, phospholipids, and steroids that are insoluble in water.
Composed of C, H, and O and containing the carboxyl group
Hydrogen and oxygen atoms exist in a greater than 2:1 ratio
Why are fats important to organisms?
Serve as long term energy storage, insulation, cell membrane composition, hormone composition
How do saturated fats form and where are they often found?
All carbon atoms in the fatty acid chains form four single bonds with hydrogen and other carbon atoms
Usually solid and dense and found in animal sources
Trans Fats
Unsaturated fats that have been synthetically converted to saturated fats by adding hydrogen (hydrogenated or partially hydrogenated vegetable oils)
What are enzymes and why are they important in organisms?
are proteins which function as a biological catalyst
Are able to lower activation energy and speed up metabolic reactions
What are the steps of bonding in fats/triglycerides?
- each fatty acid loses a hydroxyl group
- the glycerol loses 3 hydrogen atoms
-fatty acids and water combine as an ester linkage.
What are the properties of lipids?-
-hydrogen and oxygen exist in a ration that is greater than 2:1
-insoluble in water
-contain the carboxyl group
What are lipids used for in the biosphere?
-long term energy storage. insulation. cell membrane composition, hormone composition
How do saturated fats form?
-all lcarbon atoms form four single bonds with hydrogen and other atoms
what are the properties of saturated fats?
-solid and dense
-carboxyl group
How do unsaturated fats form?
2+ of the carbon atoms in the fatty acid chains form double bonds
what do the prefixes mono and poly mean in regard to unsaturated fats?
-mono vs poly unsaturated indicates the number of double bonds present
What is the composition of a phospholipid and how does it contribute to its properties?
-1 glycerol linked to two fatty acid chains and a phosphate group
this leads it to have a hydrophilic (glycerol) head, and a hydrophobic (fatty acid) tail
why are phospholipids significant in the biosphere?
- form a bilayer on every cell membrane in the biosphere
What are steroids (cholesterol?)
-a lipid that is a precursor to hormones such as testosterone and estrogen
What is tetravalence and how does it affect carbon molecules?
carobon’s tendenecy to form 4 covalent bonds with other atoms because it has four valence electrons. This means that carbon is unlikely to form ionic bonds
What are isomers?
compounds that have the same molecular formula but different structures and therefore different properties.
What are functional groups and what are some examples
The components of a chemical reaction that are most often involved in metabolic reactions
-hydroxyl
-carboxyl
-amino acids
What is polymerization
-the formation of molecules with 3+ identical parts, which are known as monomers
What is a dimer
-a molecules composed of monomers
What is dehydration synthesis and what does it produce?
-also called a condensation reaction, it is a chemical reaction that produces water.
What is a hydroxyl group composed of?
hydrogen and oxygen!
Denaturation
Changes in pH, salt concentration, temperature, or other environmental aspects may cause an enzyme to lose its structure and folding.
How is denaturation related to homeostasis?
reserving this quaternary structure is one of the prime components of homeostasis
What happens when an enzyme is exposed to conditions outside its optimal range?
By exposing an enzymes to a pH outside of its optimal range, icauses it to be denatured, or have changes in its structure and folding. This disrputs the enzyme’s molecular configuration, and destroys its certain characteristic properties, rendering it dysfunctional
substrate
reactants of enzyme-catalyzed reactions
Why does increased enzyme concentration increase th erate of reaction?
- there is more enzyme to catalyze the reaction, which increases the rate by which the reactants within the substrate are broken down into their products.
How do amino acids bond?
Two amino acid monomers are joined by removing the hydrogen from one amino group and a hydroxide ion from the carboxyl group of another amino acid
peptide bond
The linkage between two amino acids is called a peptide bond
What is a polypeptide bond?
the linkage between 3 or more amino acids
proteins (bond definition)
A polymer of polypeptide bonds!!!!!!
What kind of atoms form polar covalent / nonpolar covalent bonds
-ONLY two IDENTICAL atoms can form a nonpolar covalent bond, because there is no difference in electronegativity
-polar covalent bonds are formed between dissimilar atoms, such as H20, because there is a greater difference in electronegativity and thus, the electrons are shared unequally
What is an exmaple of a nonpolar covalent bond and why are they so strong?
. How do any two types of amino acids differ from one another?
the chemical structure of their R groups
Which molecular structures could be found in a lipid, but not in a carbohydrate, protein, or nucleic acid?
The molecular structures that could be found in a lipid, but not in a carbohydrate, protein, or nucleic acid is a long chain made only of carbon and hydrogen atoms. These are the fatty acid chain, which are connected to glycerol.
Lipids and carbohydrates are composed of carbon, hydrogen and oxygen atoms.
Proteins and nucleic acids have nitrogen atoms
What has a hydrophilic head and a hydrophobic tail?
phospholipids, which are polymers where the top atom (glucose) is formed with polar covalent bonds, and the bottom molecules (fatty acid chains), are nonpolar covalent bonds
What are the two types of compounds and what makes them different?
-In ionic compounds, electrons are transferred between atoms of different elements to form ions
. - chemical compounds, where electrons are shared between atoms of different elements to form covalent bonds
What is biuret’s solution used to test for? What color indicates a positive test? What functional group reacts with the reagant and produces this qualitative change?
protein
-the biurets solution is originally blue and changes to violet/lavender
-amino acids and carboxyl groups react with the reagent to produce this qualitative change
What is the Sudan IV solution used to test for? What color indicates a positive test? What functional group reacts with the reagent and produces this qualitative change?
-fats
- the Sudan IV changes from maroon to reddish/orange
- the carboxyl group reacts with the reagent to produce this change
What solutions tests for polysaccharides/starch? What color indicates a positive test?
-lugol’s
-iodine
-yellow/brown
What solution test for monosaccharides/glucose? What color indicates a positive test?
-Benedict’s Solution
-it changes from blue to orange
What are the four main categories of macromolecules?
Carbohydrates, lipids, proteins, and nucleic acids
What is the primary function of nucleic acids?
Tos store genetic information for how to construct proteins
hydrolysis
-a catabolic reaction in which a water molecule splits the polymer into monomers
catabolism
A metabolic reaction that breaks down dimers and polymers to release energy from the broken bonds
anabolism
A metabolic reaction that builds dimers and polymers to store energy within the bonds
