AP Bio 2
Terms
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- cohesion
- ability to sick together
- capillary action
- allowing water to creep up narrow tubing
- carbon
- 4 electrons available to form bonds
- organic chemistry
- study of the variety and complexity of carbon molecules
- functional groups
- organic molecules that share similar properties because they have similar clusters of atoms
- hydroxyl
-
- -OH
-alcohols
-polar
-hydrophilic - carboxyl
-
-C03
-carboxylic acids
-weak acids - amino
-
-NH2
-amines
-weak bases - phosphate
-
-PO4
-organic phosphates
-acids - methyl
-
-CH3
-hydrophobic - ketone
-
-CO2
-keytones
-polar
-hydrophilic - aldehyde
-
-CHO2
-polar
-hydrophilic - carbohydrates
- 3 groups according to number of sugar molecules present
- monosaccharides
-
-simplest carb
ex. fructose/glucose - disaccharides
-
-consists of 2 linked sugar molecules
ex. glucose + fructose= sucrose - polysaccharides
- consists of a series of connected monosaccharides
- polymer
- any molecule that consists of a repeating molecular unit
- starch
-
-a polysaccharide made of 1000 or more a-glucose molecules
-used in plants for energy storage - lipids
- -insoluble in water but soluble in nonpolar substances
- saturated (fatty acid)
- -has single covalent bond between each pair of carbon atoms and each carbon has 2 hydrogens bonded to it
- unsaturated (fatty acid)
- -a double covalent bond replaes a single covalent bond and 2 hydrogen atoms
- phospholipids
- -simplar to lipids except one of fatty acid chains is replaced by a phosphate group
- steroids
-
-classified with lipids
-backbone of 4-linked carbon rings - protein
- -polymers of amino acids (covalently bonded)
- peptide bonds
- bonds between amino acids
- 4 levels of the structure of a protein
-
1. primary- order of aminos 2. secondary- shape from hydrogen bonding between amino acids
-alpha-spiral
-beta pleated
3. tertiary- structure from interactions among R groups
4. quaternary- assemply from peptide chains - globular proteins
- proteins whose shape is dominated by teriary structure interactions
- metabolism
- chemical reactions that occur in biological systems
- catabolism
- breakdown of substances
- sybthesis
- formation of new products
- substrate
- substance which the ensyme acts
- denatured
- lose their 3D shape as Hydrogen bonds and peptide bonds begin to break down
- ATP
- common source of activation energy for metabolic reactions
- cofactors
- nonprotein moleclues that assist enzymes
- coenzymes
- organic cofactors
- allosteric effector
- activates or inhibits the enzyme's ability to catalyze a reaction
- feedback inhibition
- acts as an allosteric effector and shuts down one of enzymes catalyzing the reactions series
- competitive inhibition
- a substance inhibits an enzyme by occupying the active site, thus displacing the substrate
- plasma membrane/cell membrane
-
-bounds the cell
-separator of internal metabolic events from the external environment
-controls the movement of materials into and out of the cell
-consists of a double phospholipid membrane (lipid bilayer) with the nonpolar hydrophobic tails and polar hydrophilic heads - Proteins and cholesterol molecules are scattered throughout the _________.
- flexible phospholipid membrane
- phospholipid membrane
- a hydrophobic barrier to the movement of most molecules. small mulecules, such as H2O, CO2, and O2, freely pass across the membrane
- channel proteins
- provide passageways throught eh memebrane for certain water-soluble substance
- transport proteins
- spend energy (ATP) to transfer materials across the membrane.
- active transport
- the movement of solutes against a gradient with the aid of a transport protein and the expenditure of energy (usually ATP)
- recognition proteins
-
Recognize other cells and aid in sticking to other cells
-these proteins have short polysaccharide (oligosaccharide) chains attached to their surfaces extending out tfrom the cell - receptor proteins
- receptors for hormones and other trigger molecules that alicit specific cell responses
- electron transfer proteins
- involved in transferring electrons from one molecule to another during chemical reactions
- Inside the cell membrane are ________ in a a fluid cytoplasm (or cytosol).
- organelles
- organelles
- bodies that serve to physically separate the carious metabolic reactions that occur wiwthin cells.
- nucleus
- -bounded by the nuclear envelope<br />-contains chromosomes<br />-serves as the site for the separationi of chromosomes during cell division
- nuclear envelope
- -a phospholipid bilayer similar to the plasma membrane
- chromosomes
- made up of one long DNA molecule with various proteins (including histones)
- Nucleosomes
- Histone proteins served to organize the lengthy DNA, coiled into bundles
- nucleolus
- a portion of DNA that manufactures the components of ribosomes
- ribosomes
- shipped to the cytoplasm where they assemble amino acids into proteins
- endoplasmis reticulum (ER)
- -stacks of flattened sacs involved in the production of various materials
- rough ER
-
-ribosomes are attached
-serves to attach polysaccharide groups to polypeptides as they are assmbled by the ribosomes - smooth ER
-
-without ribosomes
-responsible for the synthesis of lipids and hormones, especially in cells that produce these substances for export from the cell
-in liver cells, it is involved in the breakdown of toxins, drugs, and toxic by-products from cellular reactions - golgi body/complex/apparatus
-
-group of flattened sacs arranged like a stack of bowls
-modify and package proteins and lipids into vesicles, small round-shaped sacs that bud fro the ends of a Holgi body. Vesicles often migrate to and merge with the plasma membrance, releasing their contents to the outside of the cell - lysosome
-
-vesicles from Golgi bodies that contain digestive enzymes
-break down food, cellular debris, and foreign invaders such as bacteria - mitochondria
- -carry out aerobic respiration from carbohydrates
- aerobic respiration
- a process of obtaining energy in the form of ATM from carbs
- chloroplasts
-
sites wehre both the light-dependent and light independent reactions of photosynthesis occor
-consists of an outside phospholipid bilayer membrane enclosing a fluid called stroma
-light reactions occur on the thylakoid membranes, and the dark reactions occur in the stroma - photosynthesis
- the prcess of converitng energy fron sunlight to energy in chemical bonds
- microtubules
-
-made of the protein tubulin
-function to provide support and motility for cellular activites
-found in the spindle apparatus which guides the movement of chromosomes during cell division and in flagella and cilia, structures that project from the plasma membrane and provide motility to the cell - intermediate filaments
- -provides support for maintaining the shape of the cell
- microfilaments
-
-made of protein actin
-involved in cell motility
-found in muscle cells and in cells that move by changing shape, such as the amoeba - flagella and cilia
-
-structures that protrude from the cell memebrane and make wavelike movements
-classified by their lengths and by their numbers per cell: -flagella-long and few
-cilia-short and many
-structually both consist of mibrotubules arranged in a "9 + 2" array --> nine pairs of microtubules arranged in a circle surrounding a pair of microtubules - Centrioles and basal bodies
-
-acts as microtubule organizing centers, or MTOCs
-made up of nine triplets arranged in a circle - Centrioles
- -outside the nuclear envelope gives rise to the microtubules that make up the spindle apparatus used during cell division
- Basal bodies
- at the base of each flagellum and cilium and appear to organize their development
- Most plant cells lack _____.
- centrioles.
- Cell walls
-
-found in plants fungi, protists, and bacteria
-develops outside the plasma membrane
-provides support for the cell
-consists of cellulose - cellulose
- a polysaccharide made from B-glucose
- Cell walls of fungi are usually made of _____ or ______.
- cellulose or chitin
- chitlin
-
a modified polysaccharide differing from cellulose in that one of hydroxyl groups is replaced by a group containing nitrogen
-makes up exoskeleton of arthropods - vacuoles
-
-found in plants
-fluid filled bodies that occupy the major portion of the plant cells
-maintains cell ridigity by the turgor on the cell walls - turgor
- pressure
- peroxisomes
-
-single-membrane organelles that break down various substances
-common in livers of animals (where they break down toxic substances) or in plant cells where they break down toxic by-products of certain photosynthetic processes - Differences in plant and animal cells
-
1. Plant cells have cell walls. Animal cells don't.
2. Plant cells have chloroplasts. Animal cells don't.
3. Plant cells OFTEN have large central vacuoles. Animal cells don't.
4. Animal cells have centrioles. Plant cells USUALLY don't. - Eukaryotic organisms
- all living thigns except for bacteria and cyanobacteria
- Differences in eukarotes and prokaryotes
-
1. The hereditary material exists as a single "nakes" DNA molecule without the proteins that are associated with the DNA in eukaryotic chromosomes
2. Prokaryotic ribosomes are smaler than those of eukaryotes
3. The cell walls of bacteria, when present are constructed from peptidoglycans, a polysacharide- protein molecule
4. Flagella, when present, are not constructed of microtubules - Bulk flow
-
overall movement of a group of substances
ex. blood moving through a blood vessel - Concentraction gradient
- Concentration of certain molecules/atoms/ions is different from one region to another, then the molecules which are constantly moving will eventually become evenly distibuted.
- diffusion
-
-the net movement of substances from an area of higher concentration to an area of lower concentration
-occurs as a result of the RANDOM motion of the moecules - selectively permeable
-
allows only certain substances to pass
ex. plasma membrane - solvent
- what something is dissolved in
- solute
- what is being dissolved
- hypertonic
- higher concentration of solute
- hypotonic
- lower concentration of sulutes
- isotonic
- equal concentration of solutes
- Energy is required when substances are moved ____ a gradient.
- against
- osmosis
- -diffusion of water molecules across a selectively permeable membrane
- osmotic pressure
-
-hydrostatic pressure built up by the movement of water into a body by osmosis
-the turgor of plant cells results from osmotic pressure - dialysis
- -diffusion of solutes across a selectively permeable membrane
- The term _________ is usually used when different solutes are separated by the use of a selectively permeable membrane.
- Dialysis
- Plasmolysis
- movement of water out of a cell (osmosis) that results in the collaspse of the cell (especially plant cells with central vacuoles)
- passive transport/facilitated diffusion
-
movement of solutes through channel proteins in a plasma membrane.
*Water can pass through the pasma membrane without the aid of specialized proteins. - exocytosis
-
the process of vesicles or other bodies fusing with the plasma membrand and releasing their contents to the outside of the cell.
*common when cell produces substances for export - endocytosis
- capture of a substance outside the cell when the plasma membrane merges to engulf it
- 3 kinds of endocytosis
-
1.Phagocytosis: "cellular eating" occurs when UNDISSOLVED material enters the cell. The plasma membrand wraps around the solid material and engulfs it. Ex. how single celled protists capture food
2. Pinocytosis: "cellular drinking" occurs when DISSOLVED substances enter the cell. The plasma memebrane wraps around the material and forms a vesicle that contains the engulfed material
3.Receptor-mediated endocytosis: occurs when specific molecules int he fluid surround the ell bond to specialized recoptors int he plasma membrane. The folding of the plasma membrane and formation of a vesicle follows. *describes how cells receive specific hormones - countercurrent exchange
-
-movement of substances between two regions in which substances are moving bulk flow
-direction of bulk flow movement in the two regions are opposite.
ex. blood in the ills of fish move through vessels in the opposite direction of the surronding water that rans past them. As a result, the rate of diffusion of oxygen from water into the blood is grealy increased. - general formula of photosynthesis
- light+ 6H2O+6CO2=C6H12O6 + 6O2
- C6H12O6, CH02, (CH2O) is..
- glucose or any carbohydrate
- The process of photosynthesis
-
1. light-absorbing pigments in plant cells
2.energy from the light is incorportated to electrons within the atoms that make up the molecule
3. this energized/excited electroms are unstable and most immedgiately re-emit the absorbed energy
4. The energy is reabsorbed by electrons of a nearby bigment molecule.
5. The process of energy absorption, followed by re-emission of energy, continues, with the energy bouncing from one pigment molecule to another.
6. The process ends when the energy is absorved by one of two special chlorophyll a molecules, P680 and P 700. - P680 and P 700
-
-represents the wavelength at which they absorb their maximum amounts of light
-are different from other chlorophyll molecules because of their association with carious nearby pigments
-P700 forms a pigment cluster called photosystem I (PS I)
-P680 forms photosynthesis II (PSII) - photophosphorylation
- process of mamking ATP from ADP and Pi (phosphorylation) using energy derived from light (photo).
- Calvin-Benson Cycle
-
"fixes" CO2
-takes chemically unreactive, inorganic CO2 and incorporates it into an organic molecule that can be used in biological systems
-in order to produce a single molecule of glucose (C6H12O6) it must repeat six times and use 6 CO2 molecules.
-Known as C3 photosynthesis because the first product formed, PGA (phosphoglycerate), contains three carbon atoms.
-aka Calvin cycle and carbon reductin cycle
*no light is directly used
--> thus these reactioins are often called light-independent reactions or dark reactions
-Basically takes CO2 from the atmosphere and the energy in ATP and NADPH to create a glucose molecule. The energy in ATP and NADPH represents energy from the sun captured during photophosphorylation.
6 CO2+ 18 ATP + 12 NADPH + H+ = 18 ADP + 18 Pi + 12 NADP+ + 1 glucose - Carboxylation
-
-6 CO2 combine with 6 RuBP to produce 12 PGA
-RUBP carboxylase, or rubisco, catalyzes the merging of CO2 and RUBP - Reduction
-
-12 ATP and 12 NADPH are used to convert 12 PGA to 12 PGAL
-The energy in the ATP and NADPH molecules is incorporated into PGAL (Phosphoglyceraldehyde), thus making PGAL a very energy-rich molecule - regeneration
-
-6 ATP are used to convert 10 PGAL to 6 RuBP
-Regenerating the 6 RUBP orginally used to combine with 6 CO2 allows the cycle to repeat - carbohydrate synthesis
-
-The remaining PGAL are used to build glucose, a common energy-storing molecule
-Glucose molecules can be combined to form disaccharides like sucrose and polysaccharides like ctarch and cellulose - thylakoids
-
suspended within the stroma are stacks of pancakelike membranes
-light- absorbing pigments and enzymes for the light-dependent reactions - granum (pl. grana)
- entire stack of thylakoids
- Chemiosmotic theory
-
-describes the mechanism by which ADP is phosphorylated to ATP
1. H+ ions (protons) accumulate inside thylakoids
2. A pH and electrical gradient across the thyladoid membrane is created- As H+ accumulate inside the thylakoid, the pH decreasesRhe H+ concentration decreases in the stroma and its pH increases. This creates a pH gradient consisting of differences in the concentration of H+ across the thylakoid membrane from a stroma pH 8 to a thylakoid pH 5 (a factor of 1000). Since H+ is positive, their accumulation on the inside of the thylakoin creates an electric gradient too.
3. ATP synthases generate ATP
-The pH and electrical gradient repesent potential energy like water dehind a dam. - channel proteins/ATP synthases
- allow the H+ to flow through the thylakoid membrane and out to the stroma. The energy generated by the passge of H+ provides the energy for the ATP synthases to phosphorylate ADP to ATP. The passage of about 3 H+ is required to generate one ATP.
- __________ is the most common protein on earth.
- Rubisco
- Photorespiration
- biosynthetic pathway that leads to the fixation of oxygen
- The purpsoe for moving ____ to bundle sheath cells is to increase the efficiency of photosynthesis.
- CO2
- C4 Photosynthesis
- -Instead of being fixed by rubisco into PGA, the CO2 combines with PEP(phosphoenolpyruvate) to form OAA. The fixing enzyme is PEP carboxylase. OAA, the first product of this pathway has 4 carbon atoms, thus thet name C4. OAA is converted to malate, and the malate is shuttled to specialized cells within the leaf, the bundle sheath cells. THere, malate is converted to pyruvate and CO2.
- Crassulacean acid metabolism (CAM)
-
the shysicology of this pathway is almost identical of C4 photosynthesis, with some changes.
-1. PEP carboxylas fixes CO2 to OAA, as in C4. Instead of malate, however, OAA is converted to malix acid.
-2. Malic acid is shuttled to the vacuole of the cell, not moved out of the cell to bundle sheath cells as in regular C4.
-3. Stomata are open at night. During the night, PEP carboxylase is active and malic acid accumulates in the cell's vacuole.
-4. Stomata are closed during the day (the reverse of other plants) Then the malic acid is shuttled out of the cabuole and converted back to OAA (requires 1 ATP to ADP), releasing CO2. The Co2 is now fixed by rubisco, and the Calvin-Benson cycle proceeds - advantage of CAM
- photosynthesis can proceed during the day while the stomata are closed, greatly reducing H2O loss. As a resule, CAM provides an adaptation for plants that grow in hot, dry environments with cool nights.