exam 1 Flashcards
Matter
Anything that takes up space & has mass.
Elements
Cannot be broken down into other substances by chemical reactions.
Compound
2 or more elements combined in a fixed ratio.
e.g.: Na + Cl NaCl (table salt)
4 elements that make up 96% of living matter
Carbon - C
* Oxygen - O
* Hydrogen - H
* Nitrogen – N (often limiting in plants)
CHNOPS
Carbon, Hydrogen, Nitrogen, Oxygen, Phosphorous, Sulfur
Atoms
the smallest unit having the properties of an element
Composition of atoms
in the nucleus there is protons and neutrons. Protons- positively charged
neutrons- no charge
Electrons- (negatively charge) orbit nucleus in electron cloud
Atomic number vs. Atomic mass
Atomic number = number of protons
Atomic mass = number of protons + neutrons
Isotopes
different atomic forms of same element. Same number of protons BUT different numbers of neutrons.
Electrons energy levels
Lowest energy: shell closest to the nucleus.
Electron can absorb energy, “bumping” electron into a higher shell.
Electron will then give up energy by “falling” back to its original level/shell.
Electron shells
1st shell holds 2 electrons (1s orbital)
2nd shell holds 8 electrons (2s + 2p orbitals)
3rd shell holds 8 electrons (2s + 2p orbitals)
Valence electrons and valence shell
electrons located in the valence shell (the outermost shell).
Chemical bonds
The exchanging and sharing of electrons between atoms.
Covalent bonds
Sharing of a pair of valence electrons between 2 atoms
Electronegativity
affinity for electrons, an inherent property of each type of atom. Electronegativity increases bottom to top in a column and left to right in a row.
Polar covalent bond
occur between elements with different electronegativity. Water molecule.
Nonpolar covalent bond
occurs between elements that have the same electronegativity. Much weaker than covalent bonds.
Ionic bonds
attraction that occurs between oppositely charged ions. One atom actually strips an electron completely away from its partner because their electronegativity is so different
Cation
Positive charge ion
anion
Negative charge ion
Hydrogen bonds
The attraction between a partial positive and partial
negative is a hydrogen bond.
Van Der Waals
a weak attraction when atoms are so close that outer electron shells barely touch…Hot spots of + or - charge
Cohesion
Hydrogen bonds cause water molecules to stay close to each other
Surface tension
a measure of how difficult it is to stretch or break the surface of a liquid
Adhesion
Clinging of one substance to another
Temperature
the average kinetic energy of the molecules in a body of matter, regardless of the volume.
Specific heat
the amount of heat that must be absorbed or lost for 1g of that substance to change temperature 1oC.
Heat of Vaporization (HoV)
Energy needed to go from liquid to a gas
Solvent
The dissolving agent of a solution (water)
Solution
a liquid that is a homogenous mixture of two or more substances (salt water)
Solute
the substance that is dissolved (salt)
Aqueous solution
water is the solvent.
pH of 0-6
Acidic
pH of 8-14
basic
water pH
7
Hydrocarbons
HYDROCARBONS ARE NOT PREVALENT IN LIVING ORGANISM.
Isomers
COMPOUNDS THAT HAVE THE SAME MOLECULAR FORMULA BUT DIFFERENT STRUCTURES AND DIFFERENT PROPERTIES.
Structural Isomers
DIFFER IN THE COVALENT ARRANGEMENTS OF THEIR ATOMS. (Pentane and 2-methylbutane)
Enantiomers
Molecules that are mirror images of each other but aren’t the same.
geometric Isomers
ALL HAVE THE SAME COVALENT PARTNERSHIPS BUT THEY DIFFER IN THEIR SPATIAL ARRANGEMENTS
Cis-
on the same side
Trans-
on opposite sides
7 functional groups
Hydroxyl- polar covalent, end in OL
Carbonyl- end of carbon skeleton
carboxyl- found in carboxylic acids.
amino- acts as a base since It can accept H+, part of all amino acids.
sulfhydryl- Helps stabilize the structure of some proteins
phosphate- valence of phosphorus=5, ATP, -OH ionizes to -O
methyl- not reactive like 1-6,
Dehydration Reaction
A bond forms between 2 monomers
Hydrolysis
the chemical breakdown of a compound due to reaction with water.
Carboydrates
Sugars, -ose endings, Monosaccharides (3-7 carbons.
* Disaccharides (double sugars- 2 monosaccharides) * Polysaccharides (polymers of many sugars)
Chitin
Used to build insects exoskeletons
Splenda
zero-calorie sugar substitute
Lipids
Large molecules constructed from 2 kinds of smaller molecules. Hydrophobic compounds. NONPOLAR
Fats
Triacylglycerol or Triglycerides: 3 fatty acids attached to glycerol. Can vary in length
Saturated fatty acids
No double bonds between carbon atoms composing tail - there are as many H as possible bonded to the carbon skeleton. together tightly. (high melting point)
Unsaturated fatty acids
Have one or more double bonds in the tail. Number and locations of double bonds can vary. Kinked tails don’t pack as tightly. (low melting point)
Phospholipids
Major component of cell membranes. Not energy storage. At the surface of a cell, phospholipids are arranged in a double layer (lipid bilayer).
Phospholipids in cells
The tails point toward the interior of the membrane, away from the aqueous solution (water).
HDL (high density lipoprotein)
good cholesterol
LDL (low density lipoprotein)
bad cholesterol
Enzymatic Proteins
Selective acceleration of chemical reactions
Defensive protein
protection against disease
storage protein
storage of amino acids
transport protein
transpiration of substances
r group
the side chain
determines the unique
characteristics of the
particular amino acid
MVLLITTPH
Methionine
* Valine
* Leucine
* Lysine
* Isoleucine
* Tryptophan
* Threonine
* Phenylalanine
* Histidine (Human infants)
Mid Valley Little League is taking the Plate Home
polypeptides
A polypeptide is a strand of amino acids covalently bonded to each other. They fold.
Nucleic Acids
Deoxyribonucleic acid (DNA) and ribonucleic acid (RNA) allow living organisms to reproduce from one generation to the next.
Nucleotide
the monomer of nucleic acids.
Primary Structure
comprised of a linear chain of amino acids. Unique sequence of amino acids.
Secondary Structure
The folding of a polypeptide chain due to hydrogen bonds. contains regions of amino acid chains that are stabilized by hydrogen bonds from the polypeptide backbone.
Tertiary Structure
Chemical interactions between parts of the polypeptide determines how the protein folds.
Quaternary Structure
Interaction of more than one polypeptide chain. the association of several protein chains or subunits into a closely packed arrangement
Hydrophobic interactions
nonpolar side chains usually cluster at the core of the protein
Denaturation
Proteins structure can be altered. by numerous conditions: environmental such as TEMP and pH
Why do cells have a large surface era?
- Cells are sites of a lot of chemical activity
- Cells rely on the passage of nutrients, oxygen, and wastes into and out of its cytoplasm through the plasma membrane
- Cells can only increase in size to a certain extent
- The rate substances are taken into and removed from the cell depends on surface area
- If cells were big, portions of it would not receive adequate nutrients or waste would build up
plasma membrane
barrier to passage of most molecules. Selective, regulated permeability.
Cytosol
semifluid jellylike substance
inside the plasma membrane.
Chromosomes
carry genes in the form of DNA
Ribosomes
complexes that make proteins
Prokaryotes
-Generally smaller than Eukaryotes
-DNA concentrated in Nucleoid
-lacks membrane enclosed organelles
“pre kernel”-DNA is concentrated in a nonmembrane bound region.
- Domains= Bacteria and Archaea
- “True” bacteria, blue-green alga
Eukaryotes
“true kernel.” DNA is in a membrane bound nucleus
- “kernel” = nucleus
- Domain Eukarya = animals, plants,
fungi, true algae, protists.
Plant vs. Animal cells
Most organelles and structures are found in both plant and animal cells
Animal cells have the following organelles that plant cells do NOT have
* Lysosomes * Centrioles * Flagella
Plant cells have the following organelles that animal cells do NOT have
* Chloroplasts
* Central vacuole
* Cell wall with plasmodesmata
Nucleus
Contains most of the genes in eukaryotic cells.
Chromatin
the complex of DNA associated with its proteins (histones).
vesicles
small membrane “sac” used to carry proteins from one organelle to another
Endoplasmic reticulum
-Endoplasmic = cytoplasm; reticulum= network (Latin)
-A membranous network within the cytoplasm
-Consists of membranous tubules and sacs called cisternae
-The ER membrane separates its internal compartment (lumen) from the cytosol.
-The ER is continuous with the nuclear envelope
-2 types of ER- smooth and rough
Smooth ER
Cytoplasmic surface lacks ribosomes
Golgi apparatus
Functions like a warehouse; receiving, sorting, shipping and some manufacturing
Lysosomes
An acidic membrane- enclosed bag of hydrolytic enzymes. Cells use lysosomes to digest macromolecules and parts of damaged cells.
Phagocytosis
Process of engulfing food particles
Autophagy
Recycling the cell’s own organic material
Vacuoles
Membrane-bound sacs within the cell that are larger than vesicles.
Mitochondria
Convert energy to forms the cell can use. Sites of cellular respiration - a process that generates ATP.
Chloroplast
Specialized members of a family of plant organelles called plastids. (Responsible for Photosynthesis)
Cytoskeleton
“Skeleton” and “muscles” of the cell. Necessary for strength, rigidity, force and/or motility.
Motility
Allows cells to move other proteins around
Microtubules
Straight,hollowrods composed of tubulin. MTOC- Microtubule
Organizing Center
Centrosomes and centrioles
In animal cells, microtubules grow out from centrosomes (located near nucleus). Before an animal cell divides, the centrioles replicate.
Cilia and Flagella
These are extensions from some cells. Bending results from microtubules sliding past each other, driven by motor protein dynein.
Microfilaments
Composition: rod composed of globular protein actin.
Motor- Myosin
Microfilament functions:
-Reinforce microvilli
-Amoeboid movement
-Cytoplasmic streaming
-Muscle contraction
Intermediate Filaments
Composition: rope-like filaments composed of fibrous proteins.
Function is strictly structural
No motors
Cell walls
Only found in plants, fungi, some protists, and prokaryotes
Extracellular Matrix (ECM)
Structure: interlocked extracellular fibers made of proteins, polysaccharides, glycoproteins, etc.
Most abundant glycoprotein is collagen Collagen forms strong fibers outside the
cells
1/2 total protein in human body is collagen
Tight Junctions
barrier to passage of fluid between adjacent cells.
Desmosomes
mechanical
cell-cell attachments
gap junctions
cytoplasmic continuity between adjacent cells, passage of molecules
