Quiz 1 Flashcards
Science
Guided by natural law, testable against observable world, and tentative conclusions
comparative experiments
differences between samples or groups that may differ in multiple, unknown ways
controlled experiments
manipulate one or more factors from being tested
null hypothesis
no real difference between groups
alternative hypothesis
there is a real difference in the groups
statistical significance
probability that an observed difference is not due to chance alone. we will be willing to accept a 5% chance of rejecting a null hypothesis when it is actually true
levels of biological organization
biosphere, ecosystem, community, population, organism, organ systems, tissue, cell, organelle, molecule
what determines the identity of the element?
Protons determine the identity of an element (the atomic number)
chemical reactions
the changes in distribution of electrons between atoms
chemical bond
the attractive force that links atoms together
molecule
stable association of atoms
covalent bond
strong bonds that result from sharing of electrons between atoms (strong). Sharing of valence electrons (unpaired electrons). If the two elements are close to each other on the periodic table
ionic bond
electrons transferred from one atom to another, resulting in electrostatic attraction between oppositely charged ions. Formed when one atom gains and another one loses one or more electrons (strong). Huge electronegative difference (NaCl)
Hydrogen Bond
Electrostatic attraction between slightly positive charged H and negatively charged FON atoms (weak)
Van der Waals Interactions
Transient electrostatic attractions between oppositely charged atoms. This only has non polar covalent bonds (very weak) non polar bonds are very weak. When there are many they become strong
How many covalent bonds can hydrogen make?
1 bond because they only have 1 electron
How many covalent bonds can Oxygen have?
2
How many covalent bonds can Carbon have?
They can have 4
electronegativity
attractive force that an atomic nucleus exerts on electrons of another atom
polar covalent bond
unequal sharing of electrons due to differences in electronegativities of the atoms
ion
atom that loses/gains one or more electrons. Cation is positively charged while anion is negatively charged
dipole
separation of opposite electric charges. When the main element has a weaker electronegativity than the other elements have lower electronegativities (o-c-o). The oxygens are moving away from the oxygen.
second law of thermodynamics
when an energy transformation occurs there is an increase in entropy
Is water a solvent or a solute?
it is a solvent because it is what dissolves the solvent. Ex. Water dissolves salt (salt is the solute)
hydrophilic
dissolves easily in water. Polar or charged ionic (water loving)
hydrophobic
doesn’t dissolve easily in water (water fearing). Typically non polar molecules that will not mix with polar molecules. Clump together when in water.
Does higher concentration mean more acidic or basic?
More acidic, when acids dissolve in water, they RELEASE H+ ions which can attach to other molecules and change their properties
What happens when compounds with lower concentration dissolve in water?
They will release OH- ions because they want to ACCEPT H+ ions (basic bitches need more accessories such as OH-)
Functional Groups
Methyl, Hydroxyl, Sulfhydryl, Keto, Carboxyl, Amino, Phosphate, and Aldehyde
Methyl
nonpolar (carbon attached to 3 hydrogen bonds)
Hydroxyl
Polar (O-H bond)
Sulfhydryl
Polar (S-H bond)
Aldehyde
polar (o=c-h). Important in energy releasing reactions
Keto
Polar (o=c). Included in Carbohydrates
Carboxyl
(o=c-oh)
Amino
h-n-h
Phosphate
only one with phosphorus bonds. Enters into condensation reactions. Appears at 5’ end
Macromolecules
lipids, carbohydrates, proteins, and nucleic acids. Polymers of smaller molecules called monomers joined together by covalent bonds
Lipids
nonpolar hydrocarbons, hydrophobic. are not covalently bonded with one another. If close together, they are weak but additive van der waals forces hold them together
what are fats and oils?
triglycerides
Glycerol
has 3 -OH groups and is one component of triglycerides
triglycerides
three fatty acids plus glycerol
fatty acid
non polar hydrocarbon (H2C &CH2)
ester bond
when carboxyls interact with hydroxyls of glycerol to form this bond. This is also part of a condensation reaction (pulling water out)
saturated fatty acid
all bonds are the same, no kinks. Because of the same bonds, they are able to be closer together. Saturated fats are solid at room temp. These also have a higher melting point
unsaturated fatty acids
When bonds are different, can include double and triple bonds which do not allow for compounds to squish together. These fats are liquid at room temp (plant oils). These also have a lower melting point
phospholipid
contain a glycerol, 2 fatty acids, and a phosphate containing compound. The head has a phosphate group that is hydrophilic. The tails are fatty acid chains which are hydrophobic
amphipathic
a molecule with opposing chemical properties
bilayer
sheet of two layers of lipid molecules that separates the inside and outside of cell. No water is found in the core because of hydrophobic tails inside
Carbohydrates
made up of carbon, 2 hydrogen and, oxygen. They are sources of stored energy, used to transport stored energy, carbon skeletons for other molecules, and they are extracellular structures
monosaccharides
simple sugars (make up carbs)
disaccharides
2 monosaccharides linked by covalent bonds
oligosaccharides
3-20 monosaccharides linked. They are covalently bonded to proteins and lipids on cell surfaces and act as recognition signals, ex. human blood groups
polysaccharides
hundreds to thousands of monosaccharides.
hexoses
6 carbon sugars in monosaccharide
pentoses
5 carbon sugars in a monosaccharide
gylcosidic linkages
what links monosaccharides in condensation reactions so that they can build polysaccharides/oligosaccharides (form strong fibers)
cellulose
a type of polysaccharide which is very stable and good for structural components (found in plants)
starch
a type of polysaccharide which is where the storage of glucose is in plants
glycogen
a polysaccharide that is used for glucose storage in animals
Are carbohydrates soluble in water?
Yes, they are soluble because of its polar hydroxyl groups which form hydrogen bonds with water molecules
Nucleic Acids
are polymers specialized for storage, transmission, and expression of genetic information. DNA (deoxyribonucleic acid) and RNA (ribonucleic acid) are nucleic acids
nucleotides
the monomers that make up nucleic acids. Pentose sugar (DNA or RNA), Phosphate groups, nitrogen containing base
DNA bases
ATGC
RNA bases
AUGC
phosphodiester bonds
linkage between two monosaccharides in the nucleotide (5’ carbon is linked to opposing 3’ carbon). NUCLEOTIDES ALWAYS LINK TO 3’ CARBON END. Nucleic acids grow in the 5’ to 3’ direction.
How do DNA bases pair?
they pair by hydrogen bonds. A-T form two hydrogen bonds and G-C form 3 hydrogen bonds. DO NOT MISTAKE WITH DOUBLE AND TRIPLE BONDS!
Proteins
made up of amino acids and perform all bodily functions. Contain amino acid group, carboxyl group, R side chain, and alpha carbon
R Group: Group A
they are hydrophilic because of the difference in charges. Amino acids w/ electrically charged side chains (form of NH+ and COO-). Ionic bonds can form with other amino acids
R Group: Group B
polar with uncharged side chains. Functional groups we know are polar (O-H and C-O) Covalent Bonds can form
R Group: Group D
Amino acids w/ nonpolar hydrophobic side chains
(C-H bonds). These are hydrophobic. They cluster together in an aqueous environment.
R Group- Group C (Special Cases)
Cysteine- forms CH2-SH which forms disulfide bridges. Glycine- only Hydrogen and is very small. Proline- attaches to part of the amino acid group as well as central carbon (the only one that does that)
condensation reaction
when two or more monomers join together to form a polymer with the loss of a water molecule
peptide linkages
when amino acids bond together covalently in a condensation reaction
Primary structure
sequence of amino acids
Secondary Structure
alpha helices and beta pleated sheets (they are stacked) which are connected by hydrogen bonds between the chains
tertiary structures
bending and folding results in a macromolecule with specific three dimensional shape. includes a polypeptide chain that is connected by hydrogen bonds, van der waals interactions, and ionic bonds.
disulfide linkages
covalent linkage that connect R group cysteine
Quaternary structure
results from interaction of subunits by hydrophobic interactions, van der waals forces, ionic attractions, and hydrogen bonds. Essentially multiple tertiary structures linked together
fluid mosaic model
hydrophilic heads and hydrophobic tails interacting with each other because of their properties. Van der waals and hydrophobic maintain lipid bilayers. Separation of two aqueous environments.
Where are integral proteins found?
They are embedded in lipid bilayer and can interact with both hydrophilic and hydrophobic regions
Where are peripheral proteins found?
Are not embedded but can interact with phospholipid heads
Where are anchored proteins found?
They are covalently attached to lipids which insert into the bilayer.
selective permeability
some substances can pass through but others cannot
diffusion
process of random movement towards equilibrium. Net movement from regions of greater concentration to regions of lesser concentration. Net movement is directional until equilibrium is reached
osmosis
the diffusion of water across membranes. Depends on relative concentrations of solute on each side of membrane
hypertonic
higher solute concentration. Water will want to leave cell to dilute concentration outside of it
isotonic
equal solute concentrations. Water goes in and out of cells equally.
hypotonic
water wants to enter the cell because of low solute concentration. MAKE SURE TO MAKE KNOWN WHAT IS HYPOTONIC TO WHAT (cell is hypertonic to hypotonic environment/you must make a comparison)
Passive transport
no outside energy required
active transport
energy is required to move against concentration gradient. The energy source is typically ATP
Simple Diffusion
small, nonpolar, uncharged, hydrophobic molecules can pass through the membrane. Small polar molecules can pass through (ex. H20)
facilitated diffusion
passive transport of polar/large molecule. requires specific carrier proteins
channel proteins
integral transmembrane proteins that form a channel
carrier proteins
integral transmembrane proteins that bind some substances and speed their diffusion through the bilayer
ion channels
most are gated and can be closed or opened. Gate opens when protein is stimulated to change shape by a chemical signal (ligand) or an electrical charge. Moving down concentration gradient
sodium potassium pump (Na+–K+)
active transport found in all animal cells, it is an integral member protein
vesicle
when a plasma membrane folds around material or separates from internal membrane and pinches off
exocytosis
material in a vesicle that is expelled from a cell such as waste products, secreted proteins, digestive enzymes, and neurotransmitters
endocytosis
brings materials into cell such as large particles, fluids, or large molecules
prokaryotic cells
include bacteria and archaea, Plasma membrane and cell wall. No membrane bound nucleus or other compartments
eukaryotic cells
include animals, plants, protists, and fungus. Membrane bound nucleus and other organelles. Some have cell walls (plants)
extracellular support: cell wall
used for structural support and protection. Animal cells do not have cell wall
Extracellular matrix
what animals have. Functions include: holding cells in tissues, contributing to physical properties of cartilage, skin, etc., filters materials, and orients cell movement
cytoskeleton
supports and maintains cell shape, holds organelles in position, moves organelles, interacts with extracellular structures to hold cell in place, and there are also specific proteins which provide support
organelles
found in eukaryotic cells which are surrounded by membranes to allow for an internal separation of functions within a single cell
cytoplasm
the material within the cell (except the nucleus)
nucleoid
region where cells genetic material is in prokaryotic cells
nucleus
largest organelle which contains DNA, site of gene expression, and surrounded by nuclear membrane
endomembrane system
interconnected membranes in cytoplasm. Vesicles shuttle substances between different components which include: nuclear envelope, endoplasmic reticulum (smooth and rough), and golgi apparatus
cytoplasm
liquid inside of the cell
nuclear envelope
separates the nucleus from cytoplasm which include the outer nuclear membrane and inner nuclear membrane. Pores on the outer nuclear membrane control the movement of molecules across the envelope
rough endoplasmic reticulum
ribosomes are attached. Newly made proteins enter where they are folded and transported to other regions of the cell (closest to nuclear envelope)
Smooth endoplasmic reticulum
no ribosomes and chemically modifies small molecules (furthest from nuclear envelope)
golgi apparatus
flattened sacs and small membrane enclosed vesicles. Receives proteins from the RER and can further modify them. Concentrates, packages, and sorts proteins
ribosomes
site of protein synthesis. Similar structure in both prokaryotic and eukaryotic cells. In eukaryotic cells: free ribosomes and bound to RER
mitochondria
energy in fuel molecules which is transformed into ATP (cellular respiration). Has a double membrane. Cells that require a lot of energy have many mitochondria
chloroplasts
site of photosynthesis where light energy is converted to the energy of chemical bonds. Chloroplasts have a double membrane. Not found in animal cells only plants
kinetic energy
energy of movement
potential energy
stored energy
How do you produce an energy change?
energy must be transformed/transferred from one location to another
first law of thermodynamics
energy is neither created or destroyed, energy is just changed. ex. starch in food you eat is broken down into simple sugars (release energy). Simple sugars can also be built into more complex
second law of thermodynamics
when energy is converted from one form to another, some energy will be unavailable to do work
Hydrolysis reaction
disaccharide is broken up into two monosaccharides (break glycosidic bond). ADD WATER IN, OPPOSITE OF CONDENSATION REACTION
free energy
total energy change (delta G).
exergonic reaction
free energy reaction which releases energy. Products have less energy than reactants (- delta G). Spontaneous
endergonic reactions
free energy reaction which consumes energy. Energy in products is greater than that of reactants (+delta G). Non-spontaneous
metabolism
all reactions occurring within our cells. Constantly changing where energy is depending on what cells need. All catalyzed by enzymes
Anabolic Reactions
Simple molecules and build them up into complex molecules (energy input) Exergonic reaction
Catabolic Reactions
Complex molecules broken down into simpler ones (energy output). Endergonic reaction
ATP
stores energy and gives energy in anabolic reactions and stores energy from catabolic reactions
enzymes
type of protein that helps all reactions in cells. Lowers activation energy which then speeds up reactions. Specific to our reactions, they are not going to be altered so we can use them over and over again. ex. sucrase. WILL NOT ALTER REACTION. Allows for reaction to conserve energy by lowering Ea.
enzyme-substrate complex (ES)
held together by hydrogen bonds, electrical attraction, covalent bonds, van der waals. This is when the substrate bonds to the enzyme.
substrates
reactants. Bind to specific spot called an active spot of enzyme
How do enzymes help reactions occur?
Enzyme helps put physical strain on molecule in correct place to make the reaction occur. Can orient substrates in correct orientation to get them to react together. Temporarily add chemical groups that change something about substrate. DOING SOMETHING TO SUBSTRATE TO MAKE REACTION MORE EFFICIENT RATHER THAN ALONE IN THE CELL
induced fit
enzyme can change shape to bring substrate into active site to help reaction occur
How are enzymes controlled/regulated?
Regulated by gene expression (is the enzyme being made?). Regulation of enzyme activity if already present (Can have it be active or inactive?)
inhibitors
regulators that slow down reaction rate and dont allow it to work
activators
allow enzyme to work and increase reaction rate
active site inhibition
prevent substrate from entering active site. Temporarily bound
allosteric regulation
something binds to protein/enzyme that will change its shape of active site. This will change the activity of active site (will have activating or inactivating effect). Inactive form will not bind substrate but inhibitor. Active form will bind substrate. Either covalent bonding or covalent modification
non covalent bonding
interaction between activator or inhibitor.
Regulatory peptide
changes part of protein. Two parts catalytic site and regulatory region.
catalytic peptide
can open up active site and change the shape of it
covalent modification
molecule covalently attaches to enzyme and changes shape of active site. Ex. phosphorylation (add phosphate). Kinases is an enzyme that catalyzes phosphorylation.
