Chapter 1-3 Biology Flashcards
5 characteristics of life
- Membrane-bound cells
- Replication (cells come from other cells)
- Information (central dogma)
- Energy (ATP)
- Evolution
3 Unifying Theories in Biology
- Cell Theory (Pasteur’s broth)
- Chromosomal Theory of Inheritance (Boveri-Sutton)
- Theory of Evolution (Darwin’s Finches)
Parts of the scientific method
- Theory
- Hypothesis
- Experiment
- Prediction
Theory v.s. Hypothesis v.s. Law
Theory is a broad explanation based on repeated observations and patterns.
Hypothesis is a testable and specific.
Law is a summary or mathematical statement that is known to be a fact.
Central Dogma:
DNA to RNA (__) to Protein (__)
transcription, translation
DNA base pairs?
Adenine to Thymine
Guanine to Cytosine
RNA base pairs?
Adenine to Uracil
Guanine to Cytosine
DNA is ___, meaning when DNA replicates, one strand is used as a template for synthesizing a new strand
Semi-conservative
Proteins= function,
___= function
Structure
Population
Group of individuals of the same species living in the same area at the same time
What are the 2 conditions that need to be met for natural selection to occur?
- Individuals in a population must vary in heritable traits.
- Versions of heritable traits must help individuals reproduce in certain environments.
Natural selection acts on ___.
Individuals
Evolutionary change occurs in ___.
Populations
____ occurs when populations diverge to form new species.
Speciation
Fitness
The ability to reproduce and pass on heritable traits.
Adaptation
Trait that increases fitness
Main differences between Eukaryotes and Prokaryotes
Only Eukaryotes have a nucleus.
Eukaryotes are larger.
Eukaryotes have membrane-bound organelles.
Independent variable
What you change
Dependent variable
What is being measured
Control variable
What you are comparing to
ex: the straight flask in Pasteur’s experiment
What did Louis Pasteur’s experiment disprove?
Spontaneous Generation
Genes
DNA segments on chromosomes that code for all cell products
What did Rosalind Franklin discover?
DNA’s double helix
5 Types of Bonding
- Covalent
a) Polar
b) Nonpolar - Ionic
- Hydrogen
- Hydrophobic Interactions
- Van der Waals Interactions
Which bond involves the unequal sharing of electrons?
Polar covalent
Which bond involves the equal sharing of electrons?
Nonpolar covalent
Which bond has partial charges?
Polar covalent
Which bond involves the sharing of electrons?
Ionic
Which bond has no charge?
Nonpolar Covalent
Which bond has a full charge?
Ionic
Hydrogen Bonding
When the partial positive charge of a H is attracted to a partial negative charge of another polar molecule.
Which came first, chemical or biological evolution?
Chemical
Which type of bond is hydrophobic? What should you look for?
Nonpolar covalent; Lots of C and H
Which type of bond is hydrophilic? What should you look for?
Polar covalent; Lots of N, O
Key Physical Characteristics of Water
- Small size
- Bent shape
- Highly polar covalent bonds
- Overall polarity
Molecules with more electronegativity are more ____
Polar
6 Properties of Water
- Good solvent (bc of polarity)
- Polar
- Cohesion, adhesion, surface tension
- Less dense as a solid
- High capacity for energy absorption
- Important in acid-base reactions
Cohesion v.s. Adhesion
Cohesion: attraction b/w like molecules
Adhesion: attraction b/w unlike molecules
Specific Heat
The amount of energy needed to raise temperature of 1g of substance by 1 degree celsius.
Why is the reason behind water’s high specific heat?
Hydrogen Bonds
Higher polarity mean ___
More energy needed to change the temperature
Buffers minimize changes in __
pH
Endothermic v.s. Exothermic
Endothermic must absorb thermal energy to proceed and exothermic must release it.
First Law of Thermodynamics
- Energy is conserved
- Energy can’t be created or destroyed
- Energy can’t be transferred or transformed
Second Law of Thermodynamics
Entropy, or the amount of disorder in a system, always increases
What makes a chemical reaction spontaneous?
- Proceed on their own
- No added energy needed
If products have lower potential energy than reactants then the reaction is __
Spontaneous
A reaction is spontaneous then the products are __ ordered than reactants.
Less (more polarity or electronegativity means less potential energy)
What did Miller’s Spark Discharge find?
- Heat and electrical charges formed the precursors of life
- Amino acids were created within the time the experiment was held
6 Functional Groups
- Hydroxyl
- Phosphate
- Sulfhydryl
- Amino
- Carboxyl
- Carbonyl
SH
Sulfhydryl
NH2
Amino
PO4
Phosphate
COOH
Carboxyl
CO or COOH
Carbonyl
OH
Hydroxyl
Functional groups found in amino acids
Carboxyl and Amino
Monomers are the building blocks of __
Polymers
Condensation
Monomer in, water out
Hydrolysis
Water in, monomer out
Explain why even though proteins are one of the main components of life, why they are not capable for being the sole reason of life.
Think about the five characteristics of life. Although amino acids could have polymerized to form small proteins, these proteins would need to replicate, evolve, and possess information to be considered alive.
Four Levels of Protein Structure
- Primary
- Secondary
- Tertiary
- Quaternary
(remember structure= function)
5 Parts of an Amino Acid
- H atom
- NH2 (amino functional group)
- COOH (carboxyl)
- R-group
- Central Carbon
Primary Structure
Linear structure of amino acids (there are 20 types of amino acids)
Which amino acid has a charge and which one doesn’t?
Amino acids in water would have a charged functional group (ionized), and amino acids not in water don’t (non-ionized)
Charges on a functional group help in what ways?
- Help amino acids stay in solutions
- Affect amino acid reactivity
Properties of an amino group are based on their __
R-group
Functional groups can participate in ___
Chemical reactions
If there is no functional group, there are a lot of __ and __
C, H
An acid has a ___ charge in their side chain and bases have a ___ charge.
Negative, Positive
Polar side chains have a ___ charge and can form ___ bonds.
Partial, Hydrogen
You should look for __ in polar side chains.
O
Nonpolar side chains have __ charge and you should look for __ and __.
no, C and H
Which has a more soluble r-group, hydrophilic or hydrophobic?
Both, hydrophobic is more soluble in hydrophobic solvents and vice versa.
A peptide bond is between the ___ group of one amino acid and an ___ group of another. __-__ Covalent bond results from the condensation reaction.
Carboxyl, Amino, C-N
R-groups interact with each other and ___
Water
Polymers are written from __ to __.
N-terminus to C-terminus
T/F : A peptide bond cannot rotate
True, double bonds restrict movement
T/F: Amino acid chains are not flexible
False, single bonds on either side of the peptide bond can rotate
Oligopeptide
Chain of fewer than 50 amino acids
Polypeptide
Chain of 50+ amino acids
Protein
- Term describing amino acid residue
- Complete function form of molecule
N-terminus –> __
C-terminus –> __
Nitrogen amino group
Carboxyl amino group
Which of the following is true of the peptide bond?
a) It attaches the carboxyl group of one amino acid to the carboxyl group of another
b) It’s a covalent bond formed via condensation
c) It attaches one amino group to another
d) It can rotate
b
Amino acids have which two functional groups?
Amino group and Carboxyl group
The secondary structure is formed by ___ bonds between
1. ___ group of one amino acid and
2. ___ group of another amino acid
Hydrogen bonds
Carbonyl
Amino
In the hydrogen bonds within a secondary structure, the partially positive __ is attracted to the partially negative O in the carbonyl group.
H
2 types of secondary structures
Alpha helix (curly)
Beta pleated
Tertiary structures result from interactions between __
R-groups/side-chains
Distinctive Shape of Tertiary Structure
Bending and folding
Van der Waals
Weak electrical interactions between hydrophobic side chains, quick, instantaneous
Bonds between sulfhydryl groups (disulfide)
Covalent, non polar
The backbone of secondary structures is which two groups?
Carbonyl and Amino
A chemical that breaks disulfide bonds might destroy which level of protein structure?
Tertiary
In the tertiary structures there are hydrogen bonds between the ___
R-groups
Quaternary structure is the bonding of 2+ distinct polypeptide ___. Multiple polypeptides interact to form a single functional structure.
Subunits
Think k-pop: BTS is one functional structure. Subunits are the rap line and vocal line
Dimers
Proteins with two polypeptide subunits
Homodimers
Two identical subunits
Heterodimers
Un-identical subunits
Protein structure is ___
Hierarchal
Fully functional – folded
Non-functional –> unfolded/ ____
Denatured
Which level of protein structure does not depend on any of the other levels?
Primary
Folding is __
Spontaneous
Why is a folded molecule more energetically stable than an unfolded molecule?
Folded molecule has less potential energy.
Molecular Chaperones
- Help facilitate protein folding
- Block inappropriate interactions between unfolded proteins
A hydrophobic R-group would most likely be found ___.
In the interior of a protein
Misfolding can be infectious because of ___, because they can tell other proteins to change their shape
Prions
6 Protein Functions
- Structure
- Catalysis -speed up chem reactions
- Protection -antibodies
- Transport - facilitate enter/exit
- Movement -motor proteins move cells
- Signaling -convey signals between cells
Enzymes are proteins that are ___. They hold __ in a precise orientation, so they bind to the ____ on the enzyme.
Catalysts, Substrates, Active-site
Another word for substrate is __
Reactant
Lock and Key Model
One specific substrate will bind to one specific enzyme.
Acids ___ protons and bases ___ protons
Donate, Receive
The higher the pH, the __ the protons
Fewer
