Download cell - Lakewood City School District

MIDTERM REVIEW 2016-2017
Biology
Chahda-Gonzalez
Burton
WHAT IS BIOLOGY?
Biology is the study of all living things
Living things are called organisms
Organisms include bacteria, protists, fungi, plants, &
animals
CELL THEORY
Cell theory: all living things are composed of cells, cells are the smallest unit
(structure) of living things that can perform the processes (functions) necessary for life,
living cells come only from other living cells.
Prokaryote: single celled creature (EX: bacteria)
Eukaryote: multi-celled creature (EX: cat)
PLANT VS. ANIMAL CELL
Animal Cell
Plant Cell
Cell wall
Absent
Present (formed of cellulose)
Shape
Round (irregular shape) Rectangular (fixed shape)
Vacuole
One or more small vacuole. One, large central vacuole
Centrioles
Present in all animal cells
Chloroplast
Animal cells don't have them Plant cells have chloroplasts
Plasma Membrane
Lysosomes
Only present in lower plant forms.
Only cell membrane
Lysosomes occur in cytoplasm.
Cell wall and a cell membrane
Lysosomes usually not evident.
CHARACTERISTICS OF LIFE
1. Basic Unit is the Cell
2. They Reproduce
3. All Based On Universal Genetic Code (DNA)
4. Grow & Develop
5. Obtain & Use Materials & Energy
6. Respond To Their Environment
7. Maintain A Stable Internal Environment (homeostasis)
8. Living Things Evolve, That Is They Change Over Time
SCIENTIFIC METHOD
Observation, Hypothesis, Experiment, Data Collection, Conclusion, Retest
 An experimenter changes one factor and observes or measures what happens.
 The experimenter makes a special effort to keep other factors constant so that they will not effect the
outcome.
 Those factors are called control variables.
 An independent variable is the variable that is changed or controlled in a scientific experiment to test
the effects on the dependent variable.
 A dependent variable is the variable being tested and measured in a scientific experiment.
BIOCHEMISTRY
Molecule: a group of atoms bonded together. The smallest unit of a chemical compound that
can take part in a chemical reaction.
Atom: the basic unit of a chemical element.
Compound: a thing that is composed of two or more separate elements; a mixture.
Proton: a subatomic particle with a positive charge. Located in the atomic nuclei.
Neutron: a subatomic particle with no charge. Located in the atomic nuclei.
Electron: a subatomic particle with a negitive charge. Located outside the atomic nuclei in the
atomic shell.
Element: pure substance that consists of only one type of atom. EX: Carbon, C
Isotope: a radioactive element, which has a different amount of neutrons than protons
CHEMICAL BONDS
Covalent bonds: when atoms share electrons
Ionic bonds: when atoms transfer electrons
Polar bonds: A type of covalent bond between two atoms in which electrons are
shared unequally, resulting in a bond in which one atom has a slightly negative
charge and the other a slightly positive charge.
Non-polar bonds: a type of chemical bond where two atoms share a pair of
electrons with each other.
Hydrogen bonds: A chemical bond in which a hydrogen atom of one molecule is
attracted to an electronegative atom, especially a nitrogen, oxygen, or fluorine atom,
usually of another molecule.
PROPERTIES OF WATER
1.
Cohesion: water molecules stick to each other.
2.
Adhesion: water molecules stick to other surfaces. This causes water to move upward
against gravity in plant stems and to be absorbed by paper towels.
3.
Surface Tension: water has the ability to support small objects. The hydrogen bonds
between neighboring molecules cause a “film” to develop at the surface.
4.
Capillary Action: water has the ability to “climb” structures. Think about what happens
when you stick the tip of a straw in a glass of water.
5.
Ability to Dissolve: water is consider to be the universal solvent. More substances will
dissolve in water than any other liquid.
6.
Heat of vaporization: Water has a high boiling point. It takes a lot of energy to heat
water to boiling.
7.
Density qualities: Ex: ice floats on liquid water
CARBON
Having the atomic number 6, every carbon atom has a total of
six electrons. Two are in a completed inner orbit, while the
other four are valence electrons—outer electrons that are
available for forming bonds with other atoms.
The carbon atom's four valence electrons can be shared by
other atoms that have electrons to share, thus forming covalent
(shared-electron) bonds. They can even be shared by other
carbon atoms, which in turn can share electrons with other
carbon atoms and so on, forming long strings of carbon atoms,
bonded to each other like links in a chain.
PH (1-14)
pH is a measure of the hydrogen ion concentration of a solution. Solutions with a high
concentration of hydrogen ions have a low pH and solutions with a low concentrations
of H+ ions have a high pH.
MACROMOLECULES: MOLECULES OF LIFE
Biological macromolecules are the large molecules necessary for life.
 Carbohydrates
 Lipids
 Proteins
 Nucleic acids
Composed of CHONP
HOW MACROMOLECULES JOIN TOGETHER
Monomer: A single unit
Polymer: A chain of similar single units
In dehydration synthesis, OR creating bonds between molecules
by REMOVING water, monomers combine with each other via
covalent bonds to form polymers.
In hydrolysis, OR breaking down molecules by ADDING water,
polymers are broken down into smaller units or into monomers.
CARBOHYDRATE
Used for energy and structure
Built from C, H, O
Monosaccharide: simple sugars like glucose,
galactose, and fructose.
Disaccharide: double sugars like sucrose or
lactose.
Polysaccharide: long chains of monosaccharides
like cellulose or glycogen.
LIPID
Large, non-polar molecules. Phospholipids are used in the cell
membrane. They can make waxy covering in plants, pigments, and
steroids. They can also be used for energy.
They are made of C, H, O. They use more C and H than
carbohydrates.
 Triglycerol: made of a glycerol (alcohol) and 3 fatty acid chains.
 Phospholipid: a lipid with a phosphate
Saturated lipids: only single bonds between carbons
Unsaturated lipids: contain at least one double bond
PROTEIN
Composed of amino acids, proteins are used to
build cells and they do a lot of work inside an
organism. They act as enzymes to control
metabolic reactions.
 Two functional groups: Carboxyl (-COOH)
and Amino (-NH2)
They are made of C, H, O, N.
Amino acids join together to form chains called
polypeptides.
Proteins have different structures: primary,
secondary, and quaternary.
NUCLEIC ACID
Carry the genetic information in a cell. ATP is
used for energy.
It is made of subunits called Nucleotides.
DNA: Deoxyribose Nucleic Acid
RNA: Ribonucleic Acid
ATP: Energy molecule for organisms
ENZYMES
Most enzymes are proteins. They can act as catalysts to speed up a reaction.
Enzymes are not used up or changed in a reaction, they can be re-used.
Their names end in –ase.
The area where an enzyme attaches to a substrate is called an active site.
Certain things called cofactors or coenzymes can help enzymes, inhibitors stop
enzymes from working.
The activation energy is the energy required to start a reaction. Enzymes can lower
the energy required to make the reaction happen.
PASSIVE TRANSPORT
Concentration gradient: the process of particles, moving from an area with a higher
number of particles (higher concentration) to an area with a lower number of
particles (lower concentration).
Diffusion: movement along a concentration gradient.
Osmosis: movement of water along a concentration gradient.
Facilitated diffusion: movement along a concentration gradient with the help of
integral proteins.
ACTIVE TRANSPORT
Active transport: movement AGAINST the
concentration gradient.
 Phagocytosis: the process by which a cell—
often a phagocyte or a protist—engulfs a
solid particle with the help of a vesicle.
 Pinocytosis: the ingestion of liquid into a cell
with the help of small vesicles from the cell
membrane
TONICITY
Hypotonic: the inside of the cell
has LESS water than the outside,
so the water will want to go into
the cell.
Hypertonic: the inside of the cell
has MORE water than the outside,
so the water will want to leave the
cell.
Isotonic: the water is balanced
between the inside and the
outside of the cell.
PHOTOSYNTHESIS
PHOTOSYTHESIS
Photosynthesis is the
process by which plants,
some bacteria, and some
protists use the energy from
sunlight to produce sugar,
which cellular respiration
converts into ATP, the "fuel"
used by all living things.
It takes place in the
chloroplast.
THE CELL CYCLE
The cell cycle or celldivision cycle is the serie
s of events that take
place in a cell leading
to its division and
duplication of its DNA
(DNA replication) to
produce two
daughter cells.
CELLULAR RESPIRATION
Cellular respiration is what cells do to break up sugars
into a form that the cell can use as energy. This happens in
all forms of life. Cellular respiration takes in food and uses
it to create ATP, a chemical which the cell uses for energy.
It takes place in the mitochondria.
Glycolosis: the breakdown of glucose by enzymes,
releasing energy and pyruvic acid.
Krebs Cycle: the sequence of reactions by which most
living cells generate energy during the process of aerobic
respiration
Electron Transport Chain: a series of compounds that
transfer electrons from electron donors to electron
acceptors.
 Enzyme cofactors: NAD+  NADPH
CHLOROPLASTS AND MITOCHONDRIA
MITOSIS
Interphase
Prophase
Metaphase
Anaphase
Telophase
•
Cytokinesis
at the
cleavage
furrow
Diploid  diploid
MEIOSIS
Interphase
Prophase I
 Crossing over
Metaphase I
Anaphase I
Telophase I
Prophase II
Metaphase II
Anaphase II
Telophase II
Diploid  haploid
REPRODUCTION
Mitosis creates clones, exact copies.
Meiosis is for sexual reproduction.
Spermatogenesis: the creation of the male sexual reproduction cells by meiosis.
Oogenesis: the creation of the female sexual reproduction cells by meiosis.
Crossing-over: the exchange of genes between two chromosomes, resulting in non-identical
chromatids that comprise the genetic material of gametes. Creates diversity.
Nondisjunction: the failure of one or more pairs of homologous chromosomes or sister
chromatids to separate normally during nuclear division, usually resulting in an abnormal
distribution of chromosomes in the daughter nuclei.
In meiosis, the parent is DIPLOID (2n), it has the regular amount of chromosomes. The daughter
cells are HAPLOID (n), meaning they have HALF the amount of chromosomes.
DNA AND RNA
DNA: Double helix
Deoxyribose sugar
A:T, G:C
RNA: Single strand
Ribose sugar
U:A, G:C
DNA REPLICATION
The process in which cells make proteins is called protein
synthesis.
Transcription takes place in the nucleus. It uses DNA as a
template to make an RNA molecule. RNA then leaves the
nucleus and goes to a ribosome in the cytoplasm, where
translation occurs.
Translation occurs outside of the nucleus reads the genetic
code in mRNA and makes a protein.
The protein is made on the ribosome.