Exam 1 Flashcards
In a single molecule of water, two hydrogen atoms are bonded to a single oxygen atom by ________
Polar covalent bonds
Which of the following is true about a scientific theory?
It is a comprehensive set of ideas explaining a phenomenon in nature
Using only single bonds, how many hydrogen atoms would it take to covalently bond with one sulfur atom for the molecule to become most stable?
2
How many full orbitals are in oxygen?
7
What kind of bond is formed between two molecules when a transfer of electrons takes place to form the resulting molecule?
Ionic
What type of chemical reactions are responsible for linking monomers together to build polymers?
Condensation
What types of bonds are found between the monomers of proteins?
Peptide bonds
What are the monomers of proteins?
Amino acids
If you wanted to slow down or stop an enzymatic reaction, what could you do?
Change the pH of the environment
Raise the temperature to an extreme
Increasing the substrate concentration in an enzymatic reaction could overcome which of the following?
Competitive inhibition
What are the monomers of nucleus acids?
Nucleotides
What types of bonds are found between the monomers of nucleus acids?
Phosphodiester bonds
What are the characteristics of living things?
Respond to the environment Different levels of organization Made up of cells Grow and develop Obtains and uses energy Reproduce
What is the scientific theory?
A comprehensive set of ideas explaining a phenomenon in nature
Based on Pasteur’s experiment, was the spontaneous generation hypothesis supported in the straight neck flask and the swan neck flask?
Only the straight neck flask supported the hypothesis
What is spontaneous generation?
Living things can appear from non-living things
What did Pasteur’s experiment support?
All cells come from preexisting cells
What is an alternative hypothesis?
Says there is a statistical difference between the two variables
What is a Null hypothesis?
Says there is no statistical difference between the two variables
Does a supported hypothesis prove anything?
No, if a hypothesis is supported, it adds to scientific evidence that supports or does not support a claim
What is a control group?
The group that is being compared to
What is the experimental group?
The group you are testing
What is the independent variable?
The variable that is changed (you change)
What is the dependent variable?
The variable that is measured
What are constants?
Variables that are not changed throughout the experiment, the ones that remain the same
What is matter?
Takes up space and has a mass
What is an element?
Substance that is in its simplest form
What 4 elements make up 96% of life?
Nitrogen, hydrogen, oxygen, and carbon
What is a compound?
Two or more elements bonded together
What is the order of organization?
Atom Molecule Cell organelles Cell Tissue Organ Organ system Organism Population Biocenoses Ecosystem Bioma Biosphere
How many electrons and protons are in a Ca+2 ion when it’s atomic number is 20?
20 protons, 18 electrons
What is atomic number?
#of protons (Number of electrons in an uncharged atom)
What is mass number?
Protons + neutrons
What is the electron shell?
Where the electrons orbit around the nucleus
What is the orbital?
Composed of two electrons
What is the nucleus?
Composed of protons and neutrons
How many hydrogen atoms can bond with sulfur (atomic #16)?
2
What are covalent bonds?
Share electrons
Have different electronegativity
What are ionic bonds?
Transfer electrons
- cations-positively charged
- anions-negatively charged
What is a hydrogen bond?
Have electrical attraction by partial charges
- weak
- when hydrogen bonds to F, O, or N
What is the difference between Polar-covalent bonding and non-polar covalent bonding?
Non-polar: atoms spend the same amount of time around all atoms and have similar electronegativity
Polar: spends more time around one atom than the other atoms and have different electronegativity
What are the characteristics of polar covalent bonds?
- Electrons are not shared equally
- Atoms have different electronegativity
- Spend more time around one atom compared to others in the molecule
- Soluble in water
What are the characteristics of non-polar covalent bonds?
- Electrons are shared equally
- Atoms have the same electronegativity
- Atoms spend the same amount of time around all atoms
- not soluble in water
What characteristic is shared between polar and non-polar covalent bonds?
Both share electrons
What are the properties of water?
- expands when it freezes
- Great solvent
- cohesion
- adhesion
- surface tension
If a non-polar molecule is mixed in with a polar molecule, what will happen?
The two will not dissolve
The two will repel each other
What is soluble in water?
Polar molecules
Ions
LIKE DISSOLVES LIKE
What bonds form when a polar molecule mixes with water?
Hydrogen bonds
What is cohesion?
Water molecules sticking together
What is adhesion?
Water sticking to other substances
What is surface tension?
Property of the surface of water that allows a resistance of an external force
How can I link two monomers together?
Take water away (Condensation reaction)
What are proteins built from?
Amino acids
How are amino acids linked?
Peptide bonds
What is the first level of protein structure?
Primary structure: individual amino acids are linked by peptide bonds and form polypeptides
What is the second level of protein structures?
Secondary structure: protein ms fold through hydrophobic interactions and hydrogen bonding to form alpha helices or beta-pleated sheets
What is the third level of protein structure?
Tertiary structure: amino acids sidechains continue to interact and bond in different ways to form the whole protein
This structure has covalent bonds, ionic bonds, hydrogen bonds, disulfide bridges, and vanderwaal’s forces
What is the fourth level of protein structure?
Quaternary Structure: proteins interact with one another to carry out their specific functions
Which of these types of bonds are present in the TERTIARY structure?
Covalent
Ionic
Hydrogen
Vander Waal’s forces
What happens when proteins are folded incorrectly?
Misfolded proteins are called prions
Lead to cruddy diseases like Mad Cow Disease (AKA Kuru)
What do proteins make up?
Enzymes
What do enzymes do?
Lower reaction activation energies and allow reactions to occur much faster
What do enzymes require?
Specific temperature and pH
What is competitive inhibition?
When another molecule competes for the active site on the enzyme
However, the non-substrate molecule can not work with the enzyme, meaning it can still carry out its job
-means fewer places for the substrate to bind with the enzyme
This type of inhibition can be overcome by increasing the amount of substrate
What is non-competitive inhibition?
When another molecule binds to the enzyme and changes it’s confirmation
Means the substrate is no longer able to bind and carry out the enzymatic reaction
This type of inhibition can only be overcome with Allosteric Activation
What does allosteric activation do?
It activates an inhibited enzyme/substrate complex
With allosteric activation, a molecule binds on to an enzyme at a site away from the activation site
- this pushes the inhibiting molecule off of the enzyme
- the enzyme’s original confirmation is restored
What is feedback inhibition?
When enough of a product is made, that product can inhibit the enzyme and tell it to not make any more product until it is needed
X binds to enzyme Y. In doing so, it changes its confirmation and substrate Z can no longer bind. When we add a large amount of substrate Z, the reaction continues again at its normal rate. What type of inhibition is this?
Competitive
What are the building blocks of nucleic acids?
Nucleotides
What types of bonds hold nucleotides together?
Phosphodiester
What are the purines?
Adenine and guanine
What are the pyrimidines?
Thymine and cytosine
What bases bind together in DNA?
A with T
C with G
What does RNA have in place of thymine?
Uracil
What is ATP considered?
A nucleic acid
What does ATP do?
Holds energy in living organisms
Consists of an adenine, ribose sugar, and three phosphate groups
Energy comes when a phosphate is released
Which process results in the release of energy?
A phosphate group is released
A strand of DNA is made up of 20% A and 30% C. What percent of it is U?
0%
URACIL IS IN RNA
What are carbs?
Monosaccharides in ring-formation
What is starch?
Plant energy storage
What is glycogen?
Animal energy support
What is cellulose?
Structural support in plant cell walls
What is Chitin?
Structural support in the cell walls of fungi and exoskeletons
What is peptidoglycan?
Structural support in bacterial cell walls