Bio 101 AOL Material Flashcards
The five biological themes are:
Evolution
Cooperation
Homeostasis
The flow of energy
Structure determines function
What are the domains that the six kingdoms are grouped in?
Eukarya, Archaea, Bacteria
Which is true of evolution?
It is the genetic change over time
Can occur within a single species or can lead to formation of many new species
Natural Selection
What is the next level of organization directly after tissues?
Organs
The flow of energy is responsible for shaping the ecosystem
True
The scientific method is an iterative (ongoing) process
True
What is the smallest unit of life?
A cell
Geckos have the ability to walk up the walls due to weak temporary molecular attractions known as
Van der Waals forces
What are atoms when they gain and lose electrons?
Cations and anions
What is the trend of electronegativity on the period table?
Increasing electronegatively from left to right
What is the name of a process where a water molecule spontaneously splits into a positively charged hydrogen ion (H+) and a negatively charged hydroxide ion (OH-)?
Ionization
What are the unique properties of water?
Heat storage
Ice formation
High heat vaporization
Cohesion and adhesion
High polarity
What are amino acids an example of?
Monomers
Lipids (fats) are used for long-term storage
True
How does the complementary structure of DNA help its function?
Each strand of DNA mirror each other so the DNA contain two copies of information that can be passed to the next generation
What is the monomer of proteins?
Amino acids
Enzymes are examples of what kind of macromolecules?
Proteins
Which of these are true regarding DNA and RNA?
RNA is single-stranded and contains a ribose-sugar phosphate backbone; DNA is double stranded and contains a deoxyribose-sugar phosphate backbone.
All of the following are basic features of a cell except
Mitochondria
What properties of molecules influence how well they are able to cross the lipid portion of the membrane?
Size
Polarity
Charge
The nucleus is not the only organelle which contains DNA. Which other organelle(s) contain(s) DNA?
Both mitochondria and chloroplasts
The left side of the beaker in the diagram is ______ to the right side of the beaker
Hypertonic
Osmosis is the net (overall) movement of water molecules across a membrane from an area of high concentration to an area of low concentration.
True
What is the difference between active and passive transport?
Active transport requires an input of energy, passive transport does not
What are life’s most abundant atoms?
Carbon, Nitrogen ,Hydrogen, Oxygen
Hierarchy of Life
Atoms
Molecule
Macromolecule
Organelle
Cell
Tissue
Organ
Organ System
Organism
Osmosis
When water moves from high water concentration to low water concentration, and crosses a membrane
Scientific Method
Make observation
Think of a question
Formulate hypothesis
Develop testable prediction
Gather data to test predictions
Develop general theories
Six kingdoms of diversity of life
Archea
Bacteria
Protista
Fungi
Plantae
Animalia
Basic structure of atoms: Carbon atom
The innermost shell can hold up to 2 electrons
The other shells can hold up to 8 electrons
Giving up electron or accepting electrons
= formation of iconic bonds
Sharing electrons
= formation of covalent bonds
Ions are atoms or
molecules that have full positive or negative
charges
True
Neutral Atom
Loses electrons = cation
Gains electrons = anion
True
Bond Strength:
Covalent bonds > Ionic Bonds > Hydrogen bonds
True
Ionic Bonds
involve the attraction of opposite electrical charges
Covalent bonds
form when atoms share electrons with each other
Electronegativity
a measure of how much an atom attracts
electrons.
Nonpolar covalent bond
equal sharing of electrons between 2 atoms
Polar covalent bond
unequal sharing of electrons between 2 atoms
Examples of polar molecules
Water (H2O)
Glucose sugar (C6H12O6)
Is water a polar molecule?
Yes, with 2 polar covalent bonds
Hydrogen Bonds
weak electrical attractions between the partially positive end of one polar molecule and the partially negative end of another
Hydrogen is the partially positive
end of each polar molecule
True
Hydrogen bonds are weaker and
more flexible than covalent bonds
True
van der Waals’ forces
Electrostatic interactions between atoms that have a TEMPORARY PARTIAL charge
(very weak)
Water H2O
-The chemistry of life is the water chemistry
-Water (H2O) is a polar covalent molecule
-Water can form hydrogen bonds
Cohesion and adhesion
Cohesion – when one water molecules is attracted to another
water molecule
Adhesion – When polar molecules other than water stick to water molecule
In a liquid state, water molecules tend to form the maximum number of hydrogen bonds.
True
Hydrogen bonding = water molecule & polar molecule
True
Hydrophilic molecules
molecules are
attracted to water, and water molecules cluster around hydrophilic molecules using
hydrogen bonds
Ex: polar molecules, molecules w ionic bonds
Hydrophobic molecules
Molecules are
repelled by water and do not dissolve in it
These molecules are
nonpolar and do not form hydrogen bonds
Ex: lipids (oils, fats)
pH stands for
“potential hydrogen”
The amount of hydrogen ions (H+) from water in a liquid solution can be measure as pH
Acidic solutions
have pH values
below 7
contain more
hydrogen ion (H+) than hydroxide
ions (OH- )
Basic solutions
have pH values above
7
Basic solutions contain more hydroxide ion (OH- ) than hydrogen
ions (H+)
The pH of most living cells
and their environments is
close to 7
True
Proteins involved in metabolism are sensitive to any pH changes and can
denature (unfold)
True
Buffers
(Organisms use buffers to minimize pH disturbances)
A buffer is a chemical substance that takes up or releases hydrogen ions
* Buffers help to maintain homeostasis (stable internal conditions).
Four types of macromolecules:
*Proteins (Enzyme): enzymes, structural support, other roles
* Nucleic acids (DNA): genetic storage of information
* Carbohydrates (Starch): energy storage, structural support
* Lipids (Fats/Triaglycerol): energy storage, structural support, other roles
Polymers Are Built of Monomers
True
Macromolecules (polymers) <-monomers
Protein (polymer) macromolecule
are polymers of many
subunits called amino acids (monomer)
The functional group gives amino acids their
chemical identity.
* There are 20 different types of amino acids
R- Group
True
R groups differ
between amino acids, and that these
difference will influence the shape
and function of a protein
True
Amino Acids linked together by Peptide Bond
The covalent bond
linking two amino
acids together is
called a peptide
bond.
The assembled
polymer is a called
polypeptide
The order of amino acids affects
how the polypeptide chain fold
together.
* The way that a polypeptide folds
together determines the protein’s
function.
True
Primary structure
the sequence of amino
acids in the polypeptide
chain
Secondary structure:
the initial folding
of the polypeptide chain
Hydrogen bonds form between different parts of the polypeptide
chain
Tertiary Structure
the final 3-D shape of the polypeptide
Quaternary Structure
the spatial arrangement of
component polypeptides
in proteins composed of more than one
polypeptide chain
Monomer: Nucleotide
Polymer: Nucleic acid (DNA)
DNA Double Helix
The structure of DNA
deoxyribonucleic
acid) is a double
helix
Two strands of DNA are held together by hydrogen bonds
between bases on opposite strands
Adenine (A) pairs with thymine
(T)
* Cytosine (C) pairs with
Guanine (G)
Structure of DNA
The hydrogen bonds of the base pairs can
be broken to unzip the DNA so that
information can be copied.
* Each strand of DNA is mirror image so the
DNA contains two copies of the
information.
* Having two copies means that the
information can be accurately replicated
and passed the next generation
There are two types of nucleic acids.
-Deoxyribonucleic acid (DNA)
-Ribonucleic acid (RNA)
* uses uracil instead of thymine.
* usually composed just one strand
* has a ribose sugar instead of
deoxyribose sugar.
RNA is an important participant during
protein synthesis and DNA replication
True
Monomer: Monosaccharide
Polymer: Carbohydrate (starch)
used for energy or
sometimes act as structural molecules
Simple carbohydrates are made up of
one (monosaccharides) or two
(disaccharides) sugars (monomers)
* Complex carbohydrates are
polysaccharides (long polymers)
true
Lipids
fats and other
molecules that do not dissolve
in water (Insoluble)
-Lipids are nonpolar molecules.
* Lipids include fats,
phospholipids, and many other molecules
Fats have two types of subunits
-Fatty Acids
-Glycerol
If the maximum number of
hydrogens are attached, then the
fat is called saturated.
* If there are fewer than the
maximum attached, then the fat is
called unsaturated.
fewer hydrogens= unsaturated
what make up the
two layers of the cell
membrane
Phospholipids
Cholesterol
is embedded
within the membrane and provides flexibility
Hydrophilic (“water-loving) heads face the outside and inside of cell.
* Hydrophobic (“water-fearing’”) tails cluster within the core of the cell membrane.
True
Lipids also include:
Steroid hormones
* Testosterone, estrogen
* Rubber
* Waxes
* Pigments
* Ex. Chlorophyll in plants
* Makes leaves green and photosynthetic
The Cell Theory
-All organisms are composed of one or more cells.
-Cells are the smallest living things.
-Cells arise only by division of previously existing cells
All Cells have:
-Cell membrane (plasma membrane)
-Cytoplasm
-Genetic material (DNA)
-Ribosomes
Phospholipids
polar head
nonpolar tail
Prokaryotes vs. Eukaryotes
Eukaryotic cell
* Has a nucleus and other membrane-
bound organelles
* All other kingdoms (Animalia, Plantae,
Fungi, and Protista) have this cell type
Prokaryotic cell
* Lacks a nucleus and does not have an
extensive system membrane-bound
organelles.
* All bacteria and archaea have this cell
type
Cholesterol acts like a
“buffer” for membrane
fluidity
True
Temperature decrease = decreasing fluidity
Prokaryotes are the simplest cellular
organism
True
Organelle:
a structure that performs a
particular process
* Mitochondria, chloroplast, Golgi complex,
lysosomes, endoplasmic reticulum
The cytoplasm is semi-fluid and contains
a network of protein fibers that form a
scaffold called cytoskeleton
True
- The cells of plants, fungi, and many protists have a cell wall
external to the cell membrane. - Cells of plants and protists contain chloroplasts.
- Plant cells contain a central vacuole.
- Plant cells also have a plasmodesmata (connective openings in the cell wall)
True
Endosymbiotic Theory:
These energy-harvesting organelles were derived from
ancient bacteria that were taken up by precursor
eukaryotic cells
Why does a cell need a membrane?
- To distinguish
itself from its
surroundings - To be
selective
about what
gets in and
out
Selectively permeable
some substances are able to pass through the membrane, while other substances are not able to pass through
lipid bilayers
What properties of
molecules
influence how well
they are able to
cross through the
lipid portion of the
membrane?
hydrophobic
small uncharged polar molecules
large uncharged polar molecules
ions
Direct diffusion (passive) through the lipid bilayer
Energy NOT
required
Active transport (using carrier proteins)
Membrane folding: bulk passage of materials in and out of cells (active)
Energy required
Concentration gradient:
the concentration
difference across the membrane (C1 – C2)
Hydrophobic molecules can diffuse
freely through a lipid bilayer
True
The net (overall) movement of molecules from an area of higher concentration
to an area of lower concentration is called diffusion.
* Molecules diffuse down their concentration gradient.
* Equilibrium is reached when molecules are evenly dispersed within a
confined space.
* Diffusion is a passive process that requires no input of energy.
True
Osmosis does not require
an input of energy
True
the solution with the
higher solute concentration is said to
be hypertonic,
True
and the solution with
the lower solute concentration is
said to be hypotonic
True
Free water molecules move toward
a hypertonic solution.
If the amount of solutes (dissolved
molecules) in two solutions is equal,
the solutions are isotonic to each
other.
True
Active transport utilizes protein carriers that open
only when energy (ATP) is supplied.
True
Endocytosis
is the engulfing of substances outside of the cell in order to form a vesicle that is brought
inside the cel
Exocytosis
is the discharge of substances from vesicles at the inner surface of the cell.
