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Proteins, some carbohydrates and nucleic acids are __________ of smaller molecules called __________.
___________ are not macromolecules, but some can form membranes- non-covalent interactions.
______________ are polymers with molecular weights >1,000
Macromolecular functions and interactions with other molecules depends on chemical groups called _________________ _____________.
__________ ____________ are groups of atoms with specific chemical properties and consistent behavior
_________________ are molecules with the same chemical formula, but atoms are arranged differently
___________ ____________differ in how their atoms are joined together
_____________ ___________ occur when a carbon atom has four different atoms or groups of atoms attached to it.
The four kinds of macromolecules are present in roughly the same proportions in all living organisms, and have similar functions.
Polymers are formed in ___________ _____________.
Polymers are broken down into monomers in _________ __________.
A ____________ ____________ is a single, unbranched chain of amino acids.
Amino acids have _________ and ________ groups—so they are both acid and base.
The α carbon atom is ___________(not glycine).
What are the two isometric forms of amino acids?
____________ is small and fits into tight places.
Amino group of the first amino acid: N terminus.
Carboxyl group of the last amino acid: C terminus.
____________ ____________ Bending and folding results in a macromolecule with specific three-dimensional shape.
Tertiary structure is determined by interactions of R-groups: Name these 5 interactions.
If a protein solution is heated, the secondary and tertiary structure is broken down; the protein is ____________.
____________ ___________ results from the interaction of subunits by hydrophobic interactions, van der Waals forces, ionic bonds, and hydrogen bonds.
Proteins bind specific molecules. The specificity is determined by:
Name the 4 conditions that affect secondary and tertiary structure:
Proteins can bind to the wrong molecules after denaturation/when they are newly made and still unfolded. _______ are proteins that help prevent this.
_________ are a class of stress-induced chaperone proteins. They are made by most eukaryotic cells, and many also enhance protein folding.
Carbohydrates have the general formula _____________.
Three to 20 monosaccharides
Hundreds or thousands of monosaccharides—starch, glycogen, cellulose
Most cells use ____________ (monosaccharide) as an energy source.
Monosaccharides bind together in condensation reactions to form ________ _______.
Carbohydrates can be modified by the addition of these 3 functional groups:
_________ are nonpolar molecules. Not polymers
Fats and oils are __________ (simple lipids): composed of fatty acids and glycerol
Carboxyls bond with hydroxyls of glycerol in an _______ __________.
Fatty acids are __________________: they have opposing chemical properties.
Fatty acids bound to glycerol; a phosphate group replaces one fatty acid.
_______ has ribose
_______ has deoxyribose
The “backbone” of DNA and RNA is a chain of sugars and phosphate groups, bonded by ____________ linkages.
Complementary base pairing of DNA:
All DNA molecules have ______________ structure; diversity lies in the sequence of base pairs.
All of the DNA in an organism is called its ________.
________________ is essential to the action of hormones and transmission of information in the nervous system
What is chemical evolution?
Conditions in which polymers might have been first synthesized:
__________ are folded RNA molecules that can act as catalysts.
Evidence that supports the “RNA World” hypothesis:
Today, living cells are separated from their environment by a ____________.
In water, fatty acids will form a ___________ ___________ around a compartment.
_____________ allow small molecules such as sugars and nucleotides to pass through.
•Cells are the fundamental units of life
•Functions of all cells are similar
•A site where many receptors are located.
Bacteria and Archaea are __________.
Most prokaryotes have a _______ ______ _______ outside the plasma membrane.
Bacterial cell walls contain ______________.
Some prokaryotes swim by means of ___________, made of the protein flagellin.
Some bacteria have ___________—hairlike structures projecting from the surface. They help bacteria adhere to other cells.
Some rod-shaped bacteria have a [primitive] cytoskeleton made of the protein, __________. This is a microfilament.
_________________ allowed eukaryotic cells to specialize and form the tissues and organs of multicellular organisms.
Ribosomes consist of ______________ and more than 50 different protein molecules.
free in the cytoplasm- only.
In the nucleus, DNA combines with proteins to form _________ and _________.
What is included in the endomembrane system?
The _________________ is more tubular, no ribosomes
•Composed of flattened sacs (cisternae) and small membrane-enclosed vesicles.
__________ __________ originate from the Golgi apparatus.
______________ transform the energy of fuel molecules into the phosphate anhydride bonds of ATP.
How many membranes do mitochondria have?
___________ are a site of photosynthesis—light energy is converted to the energy of chemical bonds
____________ contain chlorophyll and other pigments that harvest light energy for photosynthesis.
___________ are stacks of thylakoids—made of circular compartments of the inner membrane.
___________ is the fluid in which grana are suspended. The stroma contains DNA and ribosomes.
___________ are plastids that contain red, orange, and yellow pigments—gives color to some flowers and fruits.
___________ are plastids that store starches and fats.
•Support/maintain cell shape
•Help a cell move
In muscle, actin filaments associated with the “motor protein” ____________; interactions between the two result in muscle contraction.
Describe Intermediate Filaments.
•Tough, ropelike protein assemblages
_______ __________ undergo reversible shape changes powered by ATP hydrolysis.
Adjacent plant cells are connected by plasma membrane-lined channels called _____________.
•Holds cells together in tissues
Membranes vary in _______ composition.
________________ proteins extend all the way through the phospholipid bilayer.
Glycolipids— ____________+ _____________
Glycoproteins— ____________+ _____________
Cells arrange themselves in groups by ________________ and __________________.
Cell junctions are specialized structures that hold cells together what three things?
• Tight junctions
• Gap junctions
________________ help ensure directional movement of materials.
____________ are like “spot welds.”
_______________ allow communication.
The transmembrane protein _________ binds to the matrix outside epithelial cells, and to actin filaments inside the cells. The binding is noncovalent and reversible.
Membranes have _______________ permeability.
_________ transport—no energy required (diffusion).
Lipid-soluble molecules can diffuse across the membrane.
Electrically charged and polar molecules can not pass through easily.
Water will diffuse (net movement) from a _____________ solution across a membrane to a _____________ solution.
__________ __________ are specific channel proteins with hydrophilic pores.
Rate and direction of ion movement through channels depends on what two factors?
Water can cross a membrane by “hitchhiking” with hydrated ions, or moving through water channels called ____________.
In __________ __________, carrier proteins transport polar molecules such as glucose across membranes in both directions.
___________ ____________moves substances against a concentration and/or electrical gradient—requires energy.
___________ ___________ transport: Requires direct hydrolysis of ATP.
_____________ __________ transport: Energy comes from an ion concentration gradient that is established by primary active transport.
Macromolecules are too large to cross membranes and taken in or secreted by means of _____________ _____________.
________________ brings large molecules into a eukaryotic cell.
In ________________, molecules or entire cells are engulfed. Some protists feed in this way. Some white blood cells engulf foreign substances
In ___________, material in vesicles is expelled from a cell.
___________ is all chemical reactions in an organism.
In ________________ reactions, complex molecules are made from simple molecules; energy input is required. Synthetic.
In ___________ reactions, complex molecules are broken down to simpler ones and energy is released. Degradative.
What are bioenergetics?
Total energy = usable energy + unusable energy
enthalpy (H) = free energy (G) + entropy (S)
What is the equation for free energy (ΔG)
ΔG = ΔH – TΔS
(difference in free energy of the products and the reactants.)
Disorder tends to ___________ because of energy transformations.
Exergonic reactions _________ free energy (–ΔG): Complexity decreases (generates disorder).
Endergonic reactions __________ free energy (+ΔG): Complexity (order) increases.
At chemical equilibrium, ΔG = ______
Captures and transfers free energy.
Releases a large amount of energy when hydrolyzed.
Can donate phosphate groups to other molecules.
Hydrolysis of ATP is a _________ reaction.
____________________ is an endergonic reaction driven by ATP hydrolysis:
______________ molecules bind to the active site of the enzyme. The three-dimensional shape of the enzyme determines the specificity.
The enzyme-substrate complex (ES) is held together by ______________, _________________, or ________________.
Orient substrate molecules, bringing together the atoms that will bond.
Stretch the bonds in substrate molecules, making them unstable.
Temporarily add chemical groups to substrates.
In ____________ catalysis, enzyme side chains transfer H+ to or from the substrate, causing a covalent bond to break.
In _______________ catalysis, a functional group in a side chain bonds covalently with the substrate.
In ________________ catalysis, metals on side chains loose or gain electrons.
Binding of substrate to the active site depends on what three factors?
Many enzymes change shape when they bind to the substrate. This is called _______________.
The rate of a catalyzed reaction depends on _________________________.
Chemical reactions occur in cells simultaneously. The reactions are organized in _______________________. Each reaction is catalyzed by a specific enzyme.
______________ and _______________ regulate enzyme activity.
__________________ is when an inhibitor covalently bonds to side chains in the active site—permanently inactivates the enzyme.
______________________ is when an inhibitor bonds noncovalently to the active site and prevents substrate from binding.
_________________________ compete with the natural substrate for binding sites.
______________________ bind to the enzyme at a different site (not the active site). The enzyme changes shape and alters the active site.
An effector molecule binds to a regulatory subunit, inducing the enzyme to change its shape.
____ influences the ionization of functional groups of both the enzyme and its substrates.
In a large multicellular organism, signals reach target cells by __________ or _________.
___________ signals affect the cells that made them.
____________ signals affect nearby cells.
A signal transduction pathway involves what three things?
Receptor proteins have very specific binding sites for chemical signal molecules known as _____________.
___________ (or antagonists) can also bind to the receptor proteins.
Large or polar ligands bind to plasma membrane receptors (e.g., insulin).
Signals can be ligands (hormones) or sensory stimuli (light).
Mobile membrane proteins with 3 subunits.
Bind GDP and GTP
G proteins can either activate or inhibit an effector.
Bind ligands that can cross the plasma membrane.
Binding causes receptor to change shape to enter nucleus, affects gene expression.
cAMP has two major target types: Name them.
Protein kinases, G proteins, and cAMP are regulated by _________ that convert the activated form back to inactive form.
Multicellular organisms have cell junctions that allow communication: Name 2.
Permit metabolic cooperation between cells
Permit sharing of ATP, amino acids, coenzymes, etc.
Name the 2 most common fuels in organisms
•Chemical transformations occur in a series of reactions
_______________ is aerobic and converts pyruvate into H2O, CO2, and ATP
_____________ is anaerobic and converts pyruvate into lactic acid or ethanol, CO2, and ATP
If O2 is present (aerobic) glycolysis is followed by __________________.
If O2 is not present, pyruvate from glycolysis is metabolized by _______________.
One substance transfers electrons to another substance
________ is a key electron carrier in redox reactions.
Glycolysis takes place in the _________.
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