Exam 1 CH1-7 Flashcards
Properties of living things
- Have order
- Reproduce
- Grow, develop
- Process energy and have metabolism
- Respond to their environment
- Regulate their physiology
- Evolve
Viruses are similar to life because:
Reproduce, evolve, made of protein and DNA (ordered)
Viruses are different to life because:
Don’t metabolize, grow, regulate physiology.
Facts
Things we know are true = Statement of a phenomenon
Predictions
A way to test a hypothesis = If/then statement
Hypothesis
Explanations for facts = Phenomenon/because statement (can be supported by facts but never proven)
Inductive logic
makes general statements from many specific observations.
Descriptive science
makes general conclusions about the natural world from many observations.
Deductive logic
makes specific predictions from a general statement
Experimental science
tests specific predictions that are derived from hypotheses.
Common ancestor of life tree
Bacteria, archaea, eukaryotes.
Bacteria goes left, archaea and eukaryotes go right but separate.
Name domains that are prokaryotes
Bacteria and Archaea
Name domains that are eukaryotes
Animilia, Plantae, fungi, protist
Prokaryotes
Single celled species without nucleus and other membrane bound organelles.
Most common elements
C H O N - 96.3%, Ca P K S Na Cl Mg - 3.7%
Trace Elements
Used in small quantities ex B Cu
How was plum pudding model refuted
Plum pudding model was electrons and protons combined in an atom
Gold foil experiment disproved it
Valence Shells
3 valence shells
shell 1 - lowest energy, shell 3 - highest energy
Compound
2 or more different elements bound together in a fixed ratio.
Atom
Number of protons determines an atom’s identity.
Smallest unit of matter that retains the properties of an element.
An atoms electron distribution determines its ability to form bonds.
Broken down into protons neutrons and electrons.
Matter
Anything that takes up space
Element
A substance that cannot be broken down into anything smaller via chemical reactions.
Electrons Protons Neutrons
(-) (+) (neutral), protons and neutrons have mass of 1 dalton roughly, electrons have a mass of 1/2000 dalton.
23
NA mass #? atomic #? # of neutrons?
11
Mass # = protons + neutrons = 23
Atomic # = # of protons
Mass # - Atomic # = # of neutrons
Isotope
Having more neutrons than normal, doesn’t change the properties of atom. (Stable) - Nucleus doesn’t decay.
Radioactive Isotope
Nucleus decays spontaneously - carbon 14
Energy/Potential Energy
Energy - ability to do work (Cause Change)
Potential Energy - Energy possessed due to location or structure.
Half Life
Time it takes for 50% of the parent isotope to decay. Decays into the daughter isotope.
Radiometric Dating
Comparing the ratio between an unstable isotope and a stable one from x years ago to today. Determines through half-life calculations how long something has been fossilized.
Electron orbital
3D space where electron occupies 90% of its time.
16
S What is electron makeup?
32
1s2 2s2 2p6 3s2 3p4 - 16 electrons
Covalent Bond
The sharing of a pair of valence electrons.
Molecule
2 or more atoms held together by covalent bonds.
Valence
Number of covalent bonds that can be formed to complete an atoms valence shell. Ex: H - 1 O - 2 N - 3 C - 4.
Electronegativity
The attraction of an atom for the electrons of a covalent bond (tug of war).
Non polar covalent bond
Covalent bonds between the same atoms. Ex: H-H C=C
Polar covalent bond
2 different atoms form a covalent bond.
Ionic Bond
Two atoms that are very different in their electronegativity, the more electronegative atom strips an electron from the other atom and forms a bond. A cation and an anion.
Ex: Na and Cl, Na+Cl- is the ionic bond. All ionic bonds are salts.
Cation
Positively charged ion.
Anion
Negatively charged ion.
Hydrogen bond
A hydrogen atom apart of a molecule (partially positive charge) bonds with an electronegative (negatively charged) molecule. (weak charge)
Chemical Equillibrium
The point at which the forward and reverse reactions happen simultaneously.
The greater concentration of reactant molecules the more frequently they will collide with one another and have an opportunity to react and form products. The same holds true for products in the reverse.
Properties of water are mostly due to…
hydrogen bonding
Adhesion
High heat capacity
Hydrogen bonds dissolve in water
Do polar substances/proteins dissolve in water, if so, why?
yes, through hydrogen bonding, magnetic charge. Proteins can also dissolve in water, the polar or charged regions can form hydrogen bonds or electrostatic interactions with water molecules, allowing proteins to dissolve and remain stable in an aqueous environment. (Hydrophillic)
Do non-polar substances dissolve in water, if so, why?
No (hydrophobic), leaves hydrogen bonds exposed, not energetically favorable, water is a polar molecule.
Can water molecules dissociate?
Yes, O is much more electronegative than H, sometimes it can take an electron.
PH scale is…
negatively logarithmic.
Higher PH -> Fewer H+ ions.
Lower PH -> More H+ ions.
Organisms are made up of 4 main classes of molecules…
Proteins (50%), carbs, lipids, nucleic acid.
Large Molecules ____
Small Molecules ____
Polymers - large string of monomers.
Monomers - often have an h at one end and an oh at the other end.
Dehydration Synthesis
2 monomers to be combined chemically by the removal of a water molecule. Leaves behind a peptide bond in polypeptides, and a glycosidic bond in polysaccharides. Often occur with the help of enzymes to speed up reaction.
Hydrolysis
Polymers can be digested by adding a water molecule to seperate 2 monomers. Often occur with the help of enzymes to speed up reaction.
Enzyme
Proteins that catalyze a chemical reaction.
Amino Acid
Protein monomer, 20 dif kinds. Each has identical backbone structure with an R group (side chain) which makes it unique. Side chains can be polar, non polar, all have dif properties.
Proteins
Polymers of amino acid monomers. Called polypeptides.
How are amino acids linked together?
Dehydration synthesis between the amino and carboxyl ends of each molecule. Forms a peptide bond.
Primary Structure
Its sequence of amino acids. Ex: Ser-Glu-Gly-Asp. Sickle cell anemia, change in the primary structure.
Secondary Structure
The coils and folds that result in the proteins overall shape.
Alpha helix, beta pleated sheet
Tertiary Structure
Overall shape of a polypeptide resulting in interactions between the side chains (R Groups).
Quarternary Structure
Some proteins consist of two or more polypeptide chains aggregated into one functional macro molecule.
What determines the function of a molecule?
The shape, and the distribution of the molecular properties across that shape.
Major protein functions
Structural - Support.
Enzymatic -Increase the rate of biological reactions.
Membrane Transport - Speed up movement of substances across biological membranes.
Motile - Produce cellular movements.
Proteins are built by…
Ribosomes. Ribosomes order amino acids based on an RNA sequence. Messenger RNA is a copy of a gene - a specific sequence of DNA that corresponds to a specific protein.
Nucleotides
Monomers of DNA and RNA. Consists of a phosphate group, a 5 carbon sugar, and a nitrogenous base. Linked by dehydration synthesis in the 5’ to 3’ direction.
Pyrimidines Vs Purines
Purines have two rings, pyrimidines have one ring. Purines are A and G, pyrimidines are T U and C.
What is found in DNA?
Adenine, Cytosine, Guanine, Thymine.
What is found in RNA?
Adenine, Cytosine, Guanine, Uracil.
Difference between DNA and RNA.
Identical phosphate groups
DNA is missing an Oxygen comparing to RNA.
How are AT and CG bonded?
Hydrogen bonds. AT use 2 and CG use 3.
Carbohydrates
Short term energy storage. Use ratio 1:2:1 CHO. Monomers are bound using dehyrdation synthesis, leaves behind glycosidic linkage.
Lipids
Lipids are predominantly hydrocarbons
Nonpolar
Stores large amounts of potential energy via many covalent bonds.
Hydrophilic head, hydrophobic tail.
Form cell membranes and organelle membranes - flexible.
Saturated vs unsaturated lipids.
Saturated - single bonds hydrogen bound to carbon in every spot it can.
Unsaturated - One or more double bond carbon atoms.
Hydrocarbons
Long term energy storage because of all the c h covalent bonds.
When is hydrogen polarized vs not polarized?
When H is attached to a O or a N it is polarized, when it is attached to a C it is not polarized.
Cells have…
Order, reproductive capabilities, metabolism, and cells are the smallest hierarchical unit that conducts all processes of life.
Prokaryotic Cell
Chromosome, nucleoid, cytoplasm, ribosome, cell membrane/cell wall, flagella fimbria capsule, NO membrane bound organelles.
Eukaryotic Cell
Nucleus, cytoplasm, ribosomes, endoplasmic reticulum, golgi apparatus, mitochondria, chloroplasts, cytoskeleton and ECM, other membrane bound organelles like lysosomes, central vacuole, peroxisome, can have celll wall, centrosome, flagella.
What is a nucleus?
Inside of nucleus is nucleolus and chromatin.
Double layered phospholipid membrane that separates DNA from cytoplasm.
Pores in nuclear envelope regulate what goes in and what comes out.
Mitochondria and Chloroplast
Both have double layered membranes, their own DNA, their own ribosomes. Mitochondria generate ATP which is used by enzymes. Chloroplast absorbs light and converts it to chemical energy.
Both derived from endosymbiosis.
Cytoskeleton and Extracellular Matrix
Gives cells structure and allows them to move. Consists of long filamentous proteins.
Why are most cells microscopic… why do cells generally not get very big.
Size/physiological support- The larger the cell is the less surface area there is to support it. As size increases so does the ratio between volume and surface area.
Diffusion - Archaea and bacteria cells are not compartmentalized, no organelles bound by membranes. DNA exists in nucleoids; all chemistry occurs in cytoplasm. Due to diffusion, the cell has to be very small for rapid chemistry to be taking place, which limits how large these cells can be.
How big are cells usually (plant animal and bacteria)
Plant/Animal - 10um-100um
Bacteria - 1um-10um
Cell Membranes
Made primarily from phospholipids that are double layered. Hydrophilic head and a hydrophobic tail. Can contain proteins carbs etc, not covalently bonded so can move around.
Membranes are ____ permeable. What does this mean.
‘selectively’, this means that only certain things can diffuse through it. Other things like active transport are used to pass through membranes. Polar and charged things cannot pass through phospholipid bilayer.
Diffusion vs Facilitated diffusion
Passing through a membrane or phospholipid bilayer. Diffusion is when it passes without the aid of anything. Facilitated diffusion is when stuff passes with the aid of an enzyme.
How do secreted protein leave cells
Vesicle carries it to the edge of a cell, fuses with the cell membrane and gets rid of the proteins.
How do large molecules get in and out of cells
Endocytosis and exocytosis, respectively.
How do things pass through phospholipid bilayers (cell membranes)
1 - diffuse through phospholipids
2 - move through a channel
3 - Endo/exocytosis.
Membrane proteins can serve many functions:
1 - transportation
2 - enzymatic activity
3 - signal transduction
4 - cell-cell recognition
5 - intercellular joining
6 - attachment to cytoskeleton and extracellular matrix (ECM)
