Lecture 1-5 Flashcards
Defining characteristics of life (6).
1) exhibit order/pattern
2) process energy
3) respond to environment/stimuli
4) reproduce, grow, and develop
5) regulate internal conditions
6) adapt and evolve
What are the basics of evolution by natural selection?
- individuals of a population vary in their traits
- heritable traits are passed down from parents to offspring
- a population produces more offspring than can survive
- individuals with traits best suited for the current local environment will survive and reproduce
- suitable traits will become more and more common in the population
Important statement regarding natural selection of living organisms and their various forms/functions.
Form fits function.
Name the 10 levels of biological organization (in order).
1) Biosphere
2) Ecosystem
3) Communities
4) Populations
5) Organisms
6) Organs and organ systems
7) Tissues
8) Cells
9) Organelles
10) Molecules
Why are organisms grouped from Domain to Species?
to show relatedness and similarities
Steps of hypothesis testing.
1) observation
2) hypothesis
3) prediction
4) experiment
* if result doesn’t match the original hypothesis, repeat!
Hypothesis vs theory?
hypothesis: a proposed explanation for a phenomenon
theory: a broad scope, supported by a large body of evidence that generates testable hypotheses
What are the indigenous people’s biological knowledge and how does it relate to biologists today?
1) botany for medicines and agriculture
2) zoology for hunting, fishing and aquaculture
3) ecology for interactions and interconnectedness among organisms
Biologists: observing, classifying, monitoring, etc
Describe the polarity of water.
- covalent bond (sharing electrons)
- oxygen is more electronegative than hydrogen
- asymmetrical arrangement
- oxygen has partial negative charge
- there is cohesion between other water molecules (stick together)
- hydrogen bonding between other water molecules
Why is cohesion of water important in plant biology?
- walls of plant vessels have partial charges
- water molecules are cohesive and adhere to these walls
- stick, move up, stick, move up, stick (movement of water against gravity)
Why does hydrogen bonding of water molecules create surface tension?
- water molecules have a higher attraction to each other than to air
- creates a film
- spider can walk on water
Describe the physical states of water.
liquid to ice:
- temperature decreases
- molecules slow down
- h bonding is more ordered
liquid to gas (evaporation):
- water has to absorb more heat than an equal amount of other liquids to change physical states
- high energy water molecules move away from surface
- hydrogen bonds broken
- heat required
Why does ice float on liquid water?
ice is a solid with a larger volume and is less dense
What would happen to a lake in winter if liquid water was less dense than ice?
- freeze, sink, freeze, sink until the whole lake is frozen from top to bottom
How does water act as a solvent?
- each ion is surrounded by hydration shell (cation/anion)
- forms hydration shells around large polar molecules
What adaptations of animals in cold regions have been proven to lower the freezing point of their body fluids?
by increasing their solute concentrations
Which has a lower freezing point? Seawater or freshwater and why?
seawater due to the presence of a high solute concentration that lowers the freezing point of aqueous solutions
As pH lowers, [H+] ___ and [OH] ____ .
As pH increases, [H+] ___ and [OH] ___ .
increases, decreases
decreases, increases
If there is a pH unit change of 1, how much does this increase? A 2 pH unit change?
10 fold
10^2 = 100 fold
Identify the properties of the pH scale.
0-7 is acidic
*donates a proton to solution, increasing H+ concentration of solution
7-14 is basic
*accepts a proton from solution, decreasing H+ concentration of solution
Explain the effects of acidification of biological systems.
- decrease in pH = increased [H+]
- H+ reacts with carbonate (component in shells of aquatic organisms), decreasing ability to make shells
Explain the role of buffers.
- minimize changes in concentrations of H+ and OH- in a solution
- consists of an acid-base pair that reversibly combines with H+
How does mammal blood buffering (natural buffering) work?
H2CO3 ----- (HCO3-) + (H+) -when H+ produced, pH decreases (HCO3-) + (H+) ----- H2CO3 -reaction occurs and removes excess H+ - when H+ is used, pH increases H2CO3 ----- (HCO3-) + (H+) -adds H+ back, pH is restored
Describe the hydrocarbons.
- has only carbon and hydrogen
- stored and oxidized later to release energy
Name the functional groups that are reactive and non reactive.
reactive: hydroxyl, carbonyl, carboxyl, amino, phosphate, sulfhydryl
non-reactive: methyl
Name the functional groups that are hydrophilic and hydrophobic.
hydrophilic: hydroxyl, carbonyl, carboxyl, amino, phosphate
hydrophobic: sulfhydryl, methyl
Describe the functional group of hydroxyl.
–OH
- alcohols
- polar
- hydrogen bonds
Describe the functional group of carbonyl.
–C=O
\
- aldehydes: when terminal
ketones: when not terminal - in sugar subunits (monosacharrides)
Describe the functional group of carboxyl.
–C=O
\
OH
- polar
- can act as an acid (donate a proton)
- hydroxyl+carbonyl
Describe the functional group of amino.
H
/
--N
\
H
- amines
- acts as a base (can pick up an H+)
- also have carboxylic group
Describe the functional group of sulfhydryl.
–SH
- thiols
- cross link proteins (create dissulfied bridge)
- polar
- more hydrophilic
Describe the functional group of phosphate.
O
||
--O--P--(O-)
|
(O-)
-carry negative charge
-reacts with water releasing energy
-tends to undergo multiple chemical reactions
-releases energy stored in ATP (adenosine triphosphate)
-
Describe the functional group of methyl.
H
|
-- C -- H
|
H
- non polar
- acts as a tag on DNA
- important in gene expression
Name and explain the three types of isomers.
1) structural: different covalent arrangements of their atoms
2) geometric: same covalent arrangements, different spatial arrangements (cis and trans isomers)
3) enantiomers: mirror images of each other (but one may cause an effect and the other won’t)
Cis vs trans isomers.
cis isomers: two Xs are on the same side; create kinks and bends in biological molecules
trans isomers: two Xs are on opposite sides
Name 4 biological macromolecules.
1) proteins
2) nucleic acids
3) carbohydrates
4) lipids/fats
Name 3 biological macromolecules that are polymers.
1) proteins
2) nucleic acids
3) carbohydrates
Identify the functions of proteins (8).
1) assist chemical reactions (enzymes)
2) provide support
3) provide movement
4) store amino acids
5) coordinate organism’s activities
6) protection against disease
7) transport substances
8) cell response to chemical stimuli
What is the structure of an amino acid?
- central carbon
- carboxyl and amino functional groups
- R group/side chain (gives variety in amino acids)
- 20 different varieties of amino acids
Identifying acid or base of amino acids.
negative=acid
positive=base
Identifying polar or non polar amino acids.
non polar= methyl and hydrocarbon ring structures
polar= all other functional groups
How are polypeptides formed?
- requires energy input
- assisted by ribosomes
- has an amino and a carboxyl end/terminus (backbone)
- backbone held together by peptide bonds formed via dehydration reactions
- has side chains/ R groups
What physical interactions assist in the folding of proteins?
- aqueous environment
- non polar amino acids are shielded from water
State the trend that happens when you go down the levels of protein structure.
complexity increases as we go down the levels
Protein structure is affected by what four things? What effect does this have on the protein?
1) pH
2) solvent
3) solute concentration
4) temperature
denaturation: loss of 3D structure and loss of function
What assists in the proper folding/refolding of proteins?
chaperonins
What are the biological roles of carbohydrates?
- fuel
- carbon/energy storage
- structural component
Which suffix helps identify a monosaccharide?
“ose”
How do monosaccharides vary?
- number of carbons in skeleton
- position of carbonyl group
- ring structures
- enantiomers
Formation of glucose ring.
reaction between carbonyl of #1 carbon and hydroxyl of #5 carbon
Formation of ribose ring.
reaction between carbonyl of #1 carbon and hydroxyl of #4 carbon
Formation of fructose ring.
reaction between carbonyl of #2 carbon and hydroxyl of #5 carbon
How do the alpha and beta glucose differ from each other (ring isomers of monosaccharides)?
position of hydroxyl group on #1 carbon
What kind of bond is created during a polysaccharide polymerization?
glycosidic linkage
What are the functions of polysaccharides in both plants and animals, as well as which ones are involved?
1) structures and fibers
- cellulose in plants;
- chitin in arthropods and fungi
2) storage of surplus carbon and energy
- starch in plants
- glycogen in animals
Which is digestible by humans, starch or cellulose?
starch is digestible, cellulose is not
-this is due to humans not having the right enzymes able to break it down (cellulases)
What is the role of nucleic acids?
direct synthesis of proteins
Identify the structure of nucleotides.
- a nucleoside (nitrogenous base and pentose sugar)
- phosphate
Identify the pyrimidines and purines (nitrogenous bases) in both RNA and DNA.
pyrimidines (single ring)
- cytosine (C)
- thymine (T) in DNA
- uracil (U) in RNA
purines (double ring)
- adenine (A)
- guanine (G)
The DNA double helix is held together how?
hydrogen bonding
