Tommy Wiaduck 2014 Tommy Wiaduck Honors Biology Midterm Exam Review 2014 This study guide is an extensive collaboration of class powerpoints and independent notes. It provides a large amount of direct information. Application and use of the information ultimately depends on each individual student. It is recommended to use other resources in addition to this review. This study guide does not guarantee any scores or accuracy. If you have questions or need help in Biology, please contact Tommy Wiaduck. Topic 1: Exploring Life ● The living world is a hierarchy, with each level of biological structure building on the level below. ○ With the additional of each new level, we get new emergent properties ○ Atom > Molecule > Organelle > Cell > Tissue > Organ > Organ System > Organism > Population > Community > Biosphere ■ Biosphere: ● all environments on Earth that support life ■ Ecosystem: ● all the organisms living in a particular area ■ Community: ● the array of organisms living in a particular ecosystem ■ Population: ● all the individuals of a species within a specific area ■ Organism: ● an individual life form ■ Organ System: ● composed of organs (have specific functions) ■ Organs: ● provide specific functions for the organism ■ Tissues: ● made of groups of similar cells ■ Cells: ● living entities distinguished from their environment by a membrane ■ Organelle: ● membranebound structures with specific functions ■ Molecules: ● clusters of atoms ● Living Organisms Interact with their Environments (exchanging matter and energy) ○ interactions between living and nonliving components is required ■ producers: ● photosynthetic organisms that provide their own food ■ consumers: ● animals/organisms that profit/eat from plants ■ chemical nutrients:
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Tommy Wiaduck 2014
Tommy Wiaduck Honors Biology Midterm Exam Review 2014 This study guide is an extensive collaboration of class powerpoints and independent notes. It provides a large amount of direct information. Application and use of the information ultimately depends on each individual student. It is recommended to use other resources in addition to this review. This study guide does not guarantee any scores or accuracy. If you have questions or need help in Biology, please contact Tommy Wiaduck. Topic 1: Exploring Life
The living world is a hierarchy, with each level of biological structure building on the level below.
With the additional of each new level, we get new emergent properties Atom > Molecule > Organelle > Cell > Tissue > Organ > Organ System >
Organism > Population > Community > Biosphere Biosphere:
all environments on Earth that support life Ecosystem:
all the organisms living in a particular area Community:
the array of organisms living in a particular ecosystem Population:
all the individuals of a species within a specific area Organism:
an individual life form Organ System:
composed of organs (have specific functions) Organs:
provide specific functions for the organism Tissues:
made of groups of similar cells Cells:
living entities distinguished from their environment by a membrane Organelle:
membranebound structures with specific functions Molecules:
clusters of atoms Living Organisms Interact with their Environments (exchanging matter and energy)
interactions between living and nonliving components is required producers:
photosynthetic organisms that provide their own food consumers:
animals/organisms that profit/eat from plants chemical nutrients:
Tommy Wiaduck 2014
nonliving components required for life to be successful, an ecosystem must:
recycle chemicals necessary for life move energy through the ecosystem
energy cannot be recycled (energy enters as light ; leaves as heat)
Cells are an organism's basic units of structure and function: form generally fits function
if you change the structure, you change the function prokaryotic cells
simple and small (no membranebound organelles) bacteria
eukaryotic cells possess organelles seperated by membranes
plants, animals, and fungi All forms of life have common features
Order the complex organization of living things
Regulation/Homeostasis: ability to maintain an internal environment consisten with life
Growth and Development: consistent and specific pattern for growth/development controlled by DNA
Energy Utilization/Processing: organisms taking in energy and transforming it to do work (useful form)
Response to Environment: respond to stimuli from their environment (reaction)
Reproduction: organisms reproduce (life comes from life biogenesis)
Evolutionary Adaptation: life evolving in response to interactions between organisms and their
environment (acquisition of traits that best suit organism in environment) Three Domains for Diversity of Life
archaea: prokaryotic, often unicellular and microscopic
eukarya: eukaryotic and contain nucleus and organelles
fungi, animalia, plantae, protists Evolution Explains Unity and Diversity of Life:
Charles Darwin evolution:
biology's core theme and explains unity and diversity of life
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natural selection: individuals in a population inherit characterists that will help them
survive in an environment (only fit organisms are reproduced, slowly weeding out certain traits that prevent survival)
increases frequency of certain inherited variants/traits ex) food is high up... only taller animals can eat, shorter
animals die... species now are mainly tall The Process of Science
there are two main approaches to understand natural causes for phenomena discovery science:
provable observations and measurements to describe science hypothesisbased science:
uses data from discovery science to explain you must propose and test hypotheses
ex) Why doesn't the flashlight word? 1) Bulb or 2) Batteries
control group: all variables are held constant
experimental group: one factor or treatment is varied
theory vs. hypothesis theory:
supported by a large (and usually growing) body of evidence
hypothesis: proposed explanation for a set of osbservations
Biology and Everyday Life science and technology are interdependent
science wants to understand natural phenomena technology applies science for a specific purpose
Topic Review: 1) Describe life's hierarchy of organization
A: Atom > Molecule > Organelle > Cell > Tissue > Organ > Organ System > Organism > Population > Community > Biosphere
2) Describe living organisms' interactions with their environments
A: light from the sun goes to producers, which use it to make food (release heat energy), which is then eaten by consumers (release heat energy), and chemical nutrients cycle through the ecosystem.
3) Describe the structural and functional aspects of cells
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A: Prokaryotic Cells archaebacteria and bacteria small size ; DNA is not seperated from rest of cell no membranebound nucleus or other organelles tough external walls
Eukaryotic Cells protists, plants, fungi, animals DNA is seperated from rest of the cell (organized in chromosomes) cytoplasm surrounds nucleus and contains various organelles some have a cell wall outside plasma membrane (plant cells)
4) Explain how the theory of evolution accounts for the unity and diversity of life
A: All living species descend from ancestral species (differences reflect evolutionary change) ; natural selection
5) Distinguish between discovery science and hypothesisbased science
A: Discovery Science: use verifiable/provable observations and measurements to describe science and
phenomenas HypothesisBased Science:
use data from discovery science to explain science (you must propose and test) 6) Describe ways in which biology, technology, and societs are connected
A: technology improves our standard of living, but also brings about problems like population growth, acid rain, deforestation, global warning, endangered species, nuclear accidents, toxic waste, etc...
A: technology extends our ability to observe and measure science (improvement) Topic 2: The Chemical Basis of Life
Chemical Elements & Compounds Life requires about 25 chemical elements
element: substance that cannot be broken down there are 92 elements, only few are in a pure state
Trace elements: elements required by organisms (only in small quantities)
although you only need little of them, they are vital ex) B, Cr, Co, Cu, F, I, Fe, Mn, Mo, Se, Si, Sn, V, Zn
lack of trace elements bring about disease lack of iron: canno transport oxygen lack of iodine: holy goiter
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some are added to food/water for various reasons preserve it, more nutrious, look better
Biologically Important Elements Carbon, Oxygen, Hydrogen, and Nitrogen
C, O, H, N > make up about 96.3% of body weight/living matter Compounds
compounds are substances cosisting of two or more different elements combined in a fixed ratio
Table Salt (NaCl sodium chloride) many compounds in living organisms (including DNA) include, C, H, O,
and N Atoms and Molecules
Atoms smallest possible unit of matter that retains physical and chemical
properties of its element Subatomic Particles (3 Important): proton (+), neutron (+/)
electron () neutrons and protons are packed in an atom's nucleus
atomic number: number of protons in an atom neutral atoms have the same amount of protons and electrons
mass number: number of protons and neutrons in an atom add protons and neutrons for mass number subtract atomic number from mass number to find amount of neutrons
Isotopes: isotopes have the same number of protons and electrons, but different
numbers of neutrons ex) carbon containing 8 neutrons instead of 6 is 14C
radioactive isotops are unstable emit subatomic particles and/or energy as radioactivity they can help or hurt us
your body cannot detect isomers, but certain machines like the PET can
Electrons electron shells (orbitals) are energy levels where electrons are
atoms can have one, two, or three, electron shells number of atoms in the outermost shell determines
chemical properties of an atom 1st Shell: 2 e Max ; 2nd Shell: 8 e Max
chemical bonds attractions between atoms by sharing, donating, or receiving e's
(to fill their outer electron shells) Structural Formula: HH
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Molecular Formula: H2 Molecules: two or more atoms held together by chemical
bonds Covalent Bonds:
formed by sharing a pair of valence electrons (outer shell electrons)
Single Covalent Bond: sharing single pair of valence electrons
Double Covalent Bond: atoms shair two pairs of valence electrons (ex: O=O)
Triple Covalent Bonds: share 3 pairs of valence e's electronegativity: attraction/pull for shared electrons
DNA nitrogenous bases: Adenine (A), thymine (T), cytosine (C), and guanine (G)
RNA nitrogenous bases: A, C, G, and uracil (U)
uracil replace thymine in RNA both nitrogenous bases make up sugarphosphate backbones
repeating and protruding nitrogenous bases double helix
two polynucleotide strands wrap around each other to form the shape of DNA
A pairs with T ; C pairs with G (base pairs) RNA is usually a single polynucleotide strand
gene particular nucleotide sequence that can instruct the formation of a
polypeptide DNA molecules consist of many base pairs (and therefore,
many genes) determine the structure of protein, and thus, life's
structures and functions Deoxyribonucleid Acid (DNA)
contains coded information that programs all cell activity
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contains directions for its own replication is copied and passed from one generation of cells to the next found primarily in the nucleus makes up genes
contain instructions for proteins synthesis Ribonucleic Acid (RNA)
actual synthesis of proteins (coded for by DNA) on ribosomes in the cytoplasm messenger RNA carries encoded genetic messages
from nucleus to cytoplasm Mutations
alterations in bases or the sequence of bases in DNA lactose intolerance is a result of these mutations the gene that dictates lactose utilization is turned off in adulthood
mutations, over time, prevent the gene from turning off Topic 4: A Tour of the Cell
Cells on the Move Cells were first observed by Robert Hooke in 1665
most cells cannot be seen without a microscope Antoni van Leeuwenhoek described moving cells
not all cells move, however, the cellular parts are actively moving Light Microscope (LM)
light passes thru specimen, then thru glass lenses into viewer's eye you can magnify up to 1,000x
resolution: the ability to distinguish between small structures light microscopes cannot provide details of a small cell's structure
Electron Microscope (EM) can magnify specimens as small as 2 nanometers up to 100,000x uses a beam of electrons (as opposed to light)
Surface Area smaller the cell, larger the surface area (relative to volume)
Prokaryotic vs. Eukaryotic prokaryotic cells are structurally simpler
bacteria and archaea both have plasma membrane and 1+ chromosomes/ribosomes eukaryotic cells have membranebound nucleus (and other organelles)
prokaryotes have a nucleoid and no true organelles Eukaryotic Cells
partitioned into functional compartments
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four life processes in eukaryotic cells (depend upon structures and organelles)
Manufacturing nucleus, ribosomes, ER, and golgi
Breakdown of Molecules lysosomes, vacuoles, peroxisomes
Energy Processing mitochondria (animals) ; chloroplast (plants)
Structural Support, Movement, and Communication cytoskeleton, plasma membrane, cell wall
Animals vs. Plants Cells Lysosomes and Centrioles are not found in plant cells Plant cells have a rigid cell wall, chloroplasts, and central vacuole
(animals cells do not) Membranes
Selective Permeability plasma membrane
controls movement of molecules in and out of the cell membranes made of lipids, proteins, and carbohydrates
(phospholipids) Phospholipids form a 2layer sheet (bilayer)
hydrophilic heads face outward water loving
hydrophobic tails point inward water hating
proteins are attached to the surface Manufacturing
Endomembrane System nucleus: cell's control center (responsible for inheritence)
contains chromatin complex of proteins and DNA (makes chromosomes) DNA is copied within nucleus during interphase, before division
nuclear envelope: double membranes w/ pores allowing material to flow in and out of the nucleus
attached to a network of cellular membranes called the ER ribosomes: involved in the cell's protein synthesis ; make proteins
made in the nucleolus (inside nucleus) free ribosomes: suspended in cytoplasm bound ribosomes: attached to ER
endomembrane system: nuclear envelope, ER, golgi, lysosomes, vacuoles, and the plasma membrane
membranes in a eukaryotic cell are physically connected to compose this
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vesicles: embraneenclosed sacs that are pinched off portions of membranes, moving from the site of one membrane to another
communication results in synthesis, storage, and export of molecules
Endoplasmic Reticulum: a biosynthetic factory Smooth ER
no attached ribosomes synthesizes lipids, phospholipids, steroids, oils detoxifies drugs and poisons (usually in liver)
Rough ER attached ribosomes ; lines outer surface of membranes
synthesizes proteins (into gylcoprotein, usually) ships off to golgi in transportvesicle
Golgi Apparatus finishes, sorts, and ships
the receiving side of the golgi takes in products they are then modified as they move from one side of the golgi to
the other ships off packaged products in vesicles to other sites
Breakdown
Lysosomes digestive compartments within a cell (membranous sac containing
digestive enzymes) lack of specific lysosomes can lead to disease
remove or recycle damaged cell parts damaged part is inclosed in membrane vesicle lysosome fuses with vesicle (dismantles contests... breaks down
damaged organelle) cell destruction
"suicide sac" ; can destroy a cell if necessary Vacuoles
membraneenclosed sac that is larger than a vesicle Food Vacuole: formed by phagocytosis Contractile: pumps excess water from the cell Central Vacuole: large vacuole found in most plant cells
hydrolytic functions Summary of Endomembrane System
diagrams from power point may help understanding Energy Processing
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Energy Converting Organelles Mitochondria and Chloroplasts are the main energy transformers of cells
Mitochondria organelles which are the sites of cell respiration (found in nearly all
eukaryotic cells) Intermembrane Space:
narrow region between inner and outer membranes Mitochondrial Matrix:
enclosed by inner membrane contains enzymes used for cell respiration
Cristae: folds inside the mitochondria
Chloroplast convert solary energy to chemical energy (photosynthesis) Intermembrane Space:
seperates the double membrane Thylakoid Space:
space inside the thylakoids thylakoids: membranous sacs inside chloroplast grana: stack of thylakoids
Stroma: viscous fluid outside thylakoids
do not confuse with stomata Evolution Connection
Mitochondria and Chloroplasts evolved by endosymbiosis they both have 1) DNA and 2) ribosomes derived from prokaryotes
endosymbiosis mitochondria and chloroplasts were formerly small
prokaryotes that began living within larger cells Support, Movement, and Communication Between Cells
The Cytoskeleton provides structural suport to cells for motility and regulation
Cytoskeleton network of fibers thrughout cytoplasm that forms a dynamic framework for
support, movement, and regulation maintains cell shape (or changes it) motor proteins: organelle movement, muscle contraction
microtubules found inside cytoplasm of eukaryotic cells made of tubulin ; are hollow fibers shape the cell and act as motor protein tracks
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Centrosomes and Centrioles centirole: pair of cylindrical structures located in the centrosome of
an animal cell (nine sets of triplet microtubules arranged in ring) Cilia and Flagella
locomotor organelles found in eukaryotes that are formed from specialized arranged of microtubules
move by bending motor proteins called dynein arms Cilia: lots of tiny hairs working like the oars of a crew boat Flagella: undulates in a whiplike motion (sperm) basal body: cellular structure that anchors the microtubular
assembly of cilia and flagella microfilaments
support the cell's shape and are involved in motility provide cellular support participate in muscle contraction
Intermediate filaments reinforce cell shape and anchor organelles
Cell Surfaces and Junctions Extracellular Matrix of Animal Cells
functions in support, adhesion, movement, and development composed of strong fibers of collagen, which holds cells together and
protects the plasma membrane attaches through integrins
proteins that bind to membrane Tight Junctions
hold cells together tightly enough to block transport of substances thru intercellular space
prevent leakage of extracellular fluid Gap Junctions
specialized for transport between cytoplasm of adjacent cells channels allowing molecules to flow between cells
Anchoring Junctions fasten cells together into strong sheets, but permit substances to pass
freely Cell Walls
rigid cell walls are found in plant, buut not animal cells composed primarily of cellulose protects and provides skeletal support that keeps the plant upright against
gravity also prevents excess water uptake
plasmodesmata (plant cells have these instead of junctions) channels that perforate plant cell walls
small passage in cell wall
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connect cytoplasm of neighboring cells Topic 5: The Working Cell
Membrane Structure and Function Membranes are a fluid mosaic
composed of phospholipids and proteins surface looks mosaic because the proteins embedded in the
phospholipids appears fluid because the proteins can drift about in the
phospholipids many are made from unsaturated fatty acids (kinks in tails)
this prevents tight packing this keeps them liquid
aided by cholesterol wedged into the bilayer membranes contain integrins
integrins give the membrane stronger framework they attach to the extracellular matrix on the outside of the
cell, as well as span the membrane to attach to the cytoskeleton
glycoproteins identification tags
recognized by membrane proteins of other cells recognition
enables cells of the immune system to reject foreign cells, like infectious bacteria
membrane proteins function as enzymes signal transduction
messenger molecule > enzyme > activated molecule transport
passive: no energy required ; moves down concentration gradient
active: requires energy ; moves against concetration gradient
selective permeability some substances can cross or be transported easier than others
nonpolar molecules (CO2 and Oxygen) cross easily polar molecules (glucose, sugars) do not cross easily
Passive Transport diffusion
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process in whichparticles spread out evenly in an available space move from an area of more concentrated particles to a less
concentrated area diffuse down the concentration gradient
particles are eventually evenly spaced out requires no energy osmosis
diffusion of water across a membrane moves down concentration gradient until concentration on each
side is equal facilitated diffusion
diffusion of solutes across a membrane with the help of transport proteins Tonicity
ability of a solution to cause a cell to gain or lose water Isotonic Solution
concentration of a solute is the same on both sides Hypertonic Solution
concentration of a solute is higher outside the cell Hypotonic Solution
higher concentration of solute inside the cell osmoregulation
process that maintains water balance in cells prevents excessive uptake or loss of water plants have difficulties with osmoregulation due to cell walls
aquaporins hourglassshaped proteins that are responsible for entry and exit of water
through the membrane Active Transport
requires the use of energy / ATP moves a solute against its concentration gradient changes the shape of the protein thru phosphorylation
phosphate from ATP attaches and detaches Transport of Large Molecules
material that is transported is packaged within a vesicle this vesicle then fuses with the membrane
exocytosis export bulky molecules
such as proteins or polysaccharides endocytosis
import substances useful to livelihood of the cell phagocytosis
engulfment of a particle by wrapping cell membrane around it, forming a vacuole
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cell eating pinocytosis
engulfment of a fluid by wrapping cell membrane around it, forming small vesicles
cell drinking receptormediated endocytosis
receptors in a receptorcoated pit interact with a specific protein, initiating formation of a vesicle
Energy and the Cell energy: the capacity to do work and cause change
work is accomplished when an object is moved against an opposing force
kinetic energy: energy of motion performs work by transferring motion to other matter
ex) heat or thermal energy potential energy: energy an object possesses as a result of its location
chemical energy (energy available for release in a reaction) ex) water behind a dam
Laws of Thermodynamics thermodynamics: study of energy transformations
First Law: energy in the universe is constant
Second Law: energy conversions increase the disorder of the universe
entropy: the measure of disorder, or randomness Reaction Classification
exergonic reaction chemical reaction that releases energy
have less free energy energy is released in covalent bonds of reactants
ex) burning wood releases energy in glucose, producing heat, light, carbon dioxide, and water
ex) cellular respiration endergonic reaction
requires an input of energy yields products rich in potential energy
ex) photosynthesis metabolism
the combined makeup of thousands of endergonic and exergonic chemical reactions
metabolic pathway series of chemical reactions that either break down a complex molecule
or build up a complex molecule
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a cell's three main types of cellular work chemical work
driving endergonic reactions transport work
pumping substances across membranes mechanical work
beating of cilia energy coupling
use of exergonic processes to drive an endergonic one cells can manage energy resources this way
ATP adenosine triphosphate: energy currency of cells
immediate source of energy that powers most forms of cellular work composed of:
adenine (nitrogenous base) ribose (5carbon sugar) three phosphate grops
hydrolysis of ATP releases energy by transferring its third phosphate from ATP to another
molecule transfer is called phosphorylation ATP energizes molecules
ATP is a renewable source of energy for the cell How Enzymes Function
energy of activation (Ea) energy available to break bonds and form new ones