TEST 1 Flashcards
biology is
scientific study of life
biologists ..
ask questions and divide into themes
organelles are
various functional components of cells
all cells have
a membrane and DNA as genetic info
what is responsible for ALL reproduction, growth, and repair of multicellular organisms
Cell Division
Types of Cells
Eukaryotic and Prokaryotic
Eukaryotic cells
membrane-enclosed organelles, large & well-defined nucleus; plants, animals, humans, fungi and other forms of life
Prokaryotic Cells
simple and small, no nucleus; bacteria, archaea
DNA is
the substance of genes (what we inherit)
Chromosomes contain
DNA
A double helix is made of
2 long chains of DNA `
What is each chain made of
a link made of nucleotides (ATGC which is where all DNA comes from)
Negative Feedback
as more product accumulates, the process that creates it slow and less product is made
Positive Feedback
as more product accumulates the process that creates it speeds up and more product is made
Discovery Science
natural structures and processes - based on observation and analysis of data
Qualitative
descriptions rather than measurements (qualities)
Quantitative
recorded measurements (quantities)
Scientific Hypothesis
leads to predictions that can be tested by observation or experimentation
What must a Scientific Hypothesis be
testable and falsifiable
Matter is
anything that takes up space and has mass
Element is a
substance that cannot be broken down
Compound is
2 or more elements in a fixed ratio
Carbon, Hydrogen, Oxygen, and Nitrogen are
Elements
What forms the Atomic Nucleus
Neutrons and Protons
What is around the Nucleus (forms a cloud)
Electrons
Atomic Number is what
the number of protons
Atomic Mass is what
sum of protons and neutrons
Potential Energy is what
the energy that matter has because of its location and structure
Isotopes are
2 atoms of the same element with different number of neutrons
Valence Electrons are
electrons in the outermost shell (last shell houses valence electrons)
Valence is
the number of unpaired electrons required to complete a shell
Covalent and Ionic are
STRONG bonds
Hydrogen is
WEAK bond
3 Types of Chemical Bonds are
Covalent, Ionic, and Hydrogen
Four Major Elements that make up 95% of all living matter
Carbon, Hydrogen, Nitrogen, and Oxygen
What is the universal solvent or a biological medium
Water
Water is
Polar
What is polarity
polarity allows water molecules to form hydrogen bonds with each other
Oxygen has a _____ while Hydrogen has a _____
partially negative charge, partially positive
What are 4 Properties of Water that Sustain Life
cohesive behavior, ability to moderate temperature, expansion upon freezing, versatility as a solvent
Cohesion
hydrogen bonds hold water molecules together (cohesion)
Cohesion
attraction between different substances (adhesion)
Moderation of Temperature
water absorbs heat from warmer air & releases stored hear to cooler air
Moderation of Temperature
water can absorb/release hear with only a small change in temperature
Moderation of Temperature
Evaporative Cooling: as liquid evaporates the remaining surface cools
Expansion Upon Freezing
ice floats because hydrogen bonds in ice are more “ordered”
Water: Solvent of Life
Solution: liquid is homogenous mixture of substances
Water: Solvent of Life
Solvent: dissolving agent of a solution
Water: Solvent of Life
Solute: substance that is dissolved
Water: Solvent of Life
Aqueous Solution: where water is the solvent
Water: Solvent of Life
when ionic compound is dissolved, each ion is surrounded by a hydration shell
Hydrophilic means
“water-loving,” readily dissolved in water, molecules that contain ionic/polar covalent bonds
Hydrophobic means
“water-fearing,” NOT readily dissolvable in water, non-polar molecules like hydrocarbon
Amphipathetic Molecule means
have both polar and nonpolar regions
Acid is
any substance that INCREASES the H+ concentration of a solution
Base is
any substance that REDUCES the H+ concentration of a solution
pH scale is
acidic solutions (less than 7) & basic solutions (greater than 7); each pH unit represents a 10 fold difference in H+ and OH- concentrations
Organic Chemistry is
the study of compounds that contain carbon
Organic Compounds contain
hydrogen atoms & carbon
Electron Configuration
determines the kinds and number of bonds an atom will form with other atoms
Hydrocarbons
organic molecules consisting of ONLY CARBON & HYDROGEN; their reactions release energy
Carbon Chains vary in
size, length and branching
What is responsible for influencing the development of male and female properties
Different chemical groups (estradiol and testosterone)
What are functional groups
the components of organic molecules that are most commonly involved in chemical reactions
What are the 7 Functional Groups
hydroxyl group, carbonyl group, carboxyl group, amino group, sulfhydryl group, phosphate group, and methyl group
Hydroxyl Group
always bonded to C, hydrophilic and polar; can form hydrogen bonds with water molecules, helps dissolve organic compounds such as sugars
Carbonyl Group
acetone, double bond between C & OH; give rise to 2 major groups of sugars: aldoses and ketoses
Carboxyl Group
acetic acid, any acid will fall into this group; covalent bond between oxygen and hydrogen is so polar
Amino Group
nitrogen is involved, bent with hydrogen; acts as a base, can pick H+ from surrounding solution; ionized with a charge of 1+ under cellular conditions
Sulfhydryl Group
an S, cysteine; 2 sulfyhdral groups can react, forming a covalent bond; “cross-linking” helps stabilize protein structure
Phosphate Group
a P, glycerol phosphate provides backbone for phospholipids
Methyl Group
CH3, component of DNA, affects expression of genes, arrangement effects sex hormones
What are the 4 classes of living things
carbohydrates, lipids, proteins, nucleic acids
What is a monomer
a small building block molecule that makes up polymers
What is a polymer
a long molecule consisting of many similar building blocks (carbohydrates, proteins, and nucleic acids)
When does a Condensation/Dehydration Reaction occur
when 2 monomers bond together through the loss of water molecules
Synthesis/Breakdown of Polymers
disassembled to monomers by hydrolysis, water is added
Hydrolysis Reaction
every bond that is broken means water has been added
What is a Carbohydrate
fuel and building material
What makes up a carbohydrate
sugars and polymers of sugars
What is the simplest type of carbohydrate
monosaccharide or single sugars
What combines to form what
Monosaccharides combine to form polysaccharides (sugar polymers)
What are Monosaccharides (sugar)
a sugar, major fuel for cells and serves as raw material for building materials
Monosaccharides are usually multiples of
CH2O
What is the most common monosaccharide
glucose
how are monosaccharides classified
by location of the carbonyl group (aldose and ketose) and by number of carbons (in carbon skeleton)
Many sugars form what
rings
A _______ is formed when a _______ _________ joins two monosaccharides
disaccharide, dehydration reaction
what is the bond between 2 monosaccharides called
glycosidic linkage
what type of bond is a glycosidic linkage
covalent
polymers are made by what
a series of dehydration reactions
what are individual glucose molecules called
monosaccharides
what type of reaction would be used to build a polysaccharide
dehydration reaction
what other class of large biological molecules would catalyze this reaction
proteins (enzymes)
what is the name of the bond that holds sugars together
glycosidic linkage
What has storage and structural roles
Polysaccharides
Storage Polysaccharide
starch (plants) & glycogen (animals)
Starch (plants) do what
made of glucose monomers and plants store surplus starch
Glycogen (animals) do what
stored in liver and muscles
Structural Polysaccharides
cellulose & chitin
Cellulose is
found in cell wall of plants
Chitin is
found in exoskeleton of arthropods and provides structural support for cell walls of funghi
What are Lipids
a class of biological molecules that DO NOT form polymers, are hydrophobic, they consist of hydrocarbons and form nonpolar covalent bonds
what are 3 types of lipids
fats, phospholipids, steroids
What are 2 sub groups of fats
Glycerol and Fatty Acids
what is glycerol
3 carbon alcohol with hydroxyl group attached to each carbon
what is fatty acids
consists of a carboxyl group attached to a long carbon skeleton
what is name of function group on glycerol and fatty acids (they participate in dehydration reaction to form fats)
carboxyl group
what is Ester Linkage
a bond between a carboxyl and hydroxyl group
example of saturated fatty acids
butter
example of unsaturated fatty acids
oil
what is a phospholipid
2 fatty acids and a phosphate group attached to glycerol; 2 fatty acid tails are hydrophobic but the phosphate group and its attachment form a hydrophilic head (look at picture)
what is a steroid
lipids characterized by a carbon skeleton consisting of 4 fused rings; cholesterol is important steroid because they are present in animal cell membranes
What are main protein functions
structural support (keep its shape), transport (how materials are moved in/out of cell), cellular communication (sending messages between cells), defense against foreign substances (immune system defense (antibodies))
What are steps Enzymes (as proteins) take that catalyze or speed up a chemical reaction
- Binding to a substrate
- Conversion of Substrate to products
- Release of products from enzyme
- Enzyme free to catalyze further reactions
Enzymes function as
workhorses that carry out the process of life
T or F: All proteins are built from same set of 20 amino acids
true
what is the R group and where is it
responsible for hydrophilicity and readily forms hydrogen bonds with water and are the branch off from carbon that is not hydrogen
what does polar mean
WATER LOVING
what are amino acids linked by
peptide bonds and multiple amino acids linked together form a polypeptide
T or F: each individual protein has a unique linear sequence of amino acids
true
peptides are named from ___ to ___, starting with the _______
left, right, n-terminus
Functional proteins consists of
one or more polypeptides twisted, folded, and coiled into a unique shape
a proteins structure determines what
its function
levels of protein structure are
- primary
- secondary
- tertiary
- quaternary
Sickle Cell Disease
slight change in primary structure and can cause abnormalities; also results from a single amino acid substitution in the protein hemoglobin
T or F: A single amino acid has very little effect on hemoglobin
true
What causes a protein to unravel
alterations to pH, salt concentration, temperature, and other environmental factors
what is the loss of a protein’s native structure
denaturation
a denatured protein is
biologically inactive
what are 2 most common nucleic acids
DNA & RNA
amino acid sequence of a polypeptide is ______ by a ____ __ ___________ called a ____
programmed, unit of inheritance, gene
genes are made of what nucelic acid
DNA
T OR F: DNA provides its own instructions for replication
True
Order of Nucleic Acids
DNA–> RNA –> Protein
nucleic acids are polymers called
polynucleotides
each polynucleotide is made of monomers called
nucleotides
Each nucleotide contains
- nitrogenous base
- pentose sugar
- phosphate group
DNA is a _____ helix, an arrangement called ________
double, antiparallel
Adenine-Thymine (A-T)
2 hydrogen bonds
Guanine-Cytosine (G-C)
3 hydrogen bonds
Characteristics of Light Microscope
can see live cells, more common, less $$
Characteristics of Electron Microscope
more expensive, much more specific and precise
What is magnification
the ratio of an objects image size to its real size
what is resolution
clarity; ability to observe 2 adjacent objects as distinct from one another
what is contrast
visible, differences in parts of the sample; using dye
Eukaryotic Cell Characteristics
- fungi, animal, plants
- larger than prokaryotic
- DNA in nucleus bounded by a nuclear envelope
- membrane-bound organelles
Prokaryotic Cell Characteristics
- bacteria and archaea
- no nucleus
- no membrane-bound organelles
- Cytoplasm bound by plasma membrane
Both Prokaryotic and Eukaryotic Characteristics
- plasma membrane
- semifluid substance called cytosol
- chromosomes (carry genes)
- ribosomes (make proteins)
what is the plasma membrane
a selective barrier that allows oxygen, nutrients, and waste to service the volume of every cell
what is the general structure of a biological membrane
a double layer of phospholipids (phospholipid bilayer)
what does the Endomembrane System do
regulates protein traffic and performs metabolic functions in the cell
What components make up the Endomembrane System
- nuclear envelope
- endoplasmic reticulum
- Golgi apparatus
- lysosomes
- peroxisomes
- plasma membrane
these components are either continuous/connected by _____
vesicles
Nucleus
contains cell genes; the nuclear envelope encloses the nucleus, separating it from the cytoplasm; nuclear membrane is a double membrane; each membrane consists of a lipid bilayer
What regulates entry and exit of molecules from the nucleus
pores
the shape of the nucleus is maintained by the
nuclear lamina (which is composed of protein)
DNA and proteins form genetic material called _______
chromatin (these condense to form chromosomes)
what is located within the nucleus
nucleolus (site of ribosomal RNA (rRNA) synthesis)
what accounts for more than half of a eukaryotic cell
Endoplasmic Reticulum (is continuous with the nuclear envelope)
Smooth ER
no ribosomes, synthesizes lipids, breaks down carbohydrates and stores calcium
Rough ER
has ribosomes, secretes glycoproteins, distributes transport vesicles
Golgi apparatus
consists of flattened membranes called cistern (FEDEX HQ)
Functions of the Golgi apparatus
modifies products of ER (carbs and glycoproteins); sorts and packages materials into membrane transport vesicles
Journey of Secreted Protein
- Synthesis in the ER
- Transport through the Golgi
- Release from the plasma membrane to the outside of the cell
Lysosomes
membranous sac of hydrolytic enzymes that can digest macromolecules
Lysosomal enzymes can
hydrolyze proteins, fats, polysaccharides and nucleic acid (hydrolysis reaction) ; all organelles that can break down
Plasma Membrane
selectively permeable membrane, cell signaling using receptors, cell adhesion; boundary between cell and extracellular environment
__________ and __________ change energy from one form to another
Mitochondria and Chloroplasts
Mitochondria
site of cellular respiration and where ATP is generated
Smooth outer membrane and inner membrane of mitochondria folded into
cristae
inner membrane of mitochondria creates 2 compartments
- inter-membrane space
- mitochondrial space
Cristae presents a large surface area for enzymes that
synthesizes ATP (chemical energy conversion)
Chloroplasts
found in plants and algae and is the site of photosynthesis
chloroplasts is where
light energy is captured
chloroplasts are in the family of organelles called
plastids
chloroplasts contain a green pigment called
chlorophyll
Motor proteins interact with
cytoskeletal functions
Motor proteins
move cargo from one location in the cell to another; remains in one place and causes filament to move and bend
T or F: both motor protein and filament is restricted in their movement
true
Cytoskeleton
network of different size fibers extending throughout the cytoplasm of the cell (bones of the cell)
The cytoskeleton
supports the cell and helps keep it in shape; it helps with motility and moves material from one cellular location to another
3 fibers make up the Cytoskeleton
- Microtubules ( thickest)
- Microfilaments (thinnest; actin filaments)
- Intermediate filaments (middle thickness)
Microtubules
hollow rods that shape the cell and guide movement of vesicles and organelles; also separates chromosomes during cell division
Cilia & Flagella
microtubules control beating of cilia and flagella, they are locomotor appendages of some cell; they differ in their beating patterns
Microfilaments
solid rods build as a twisted double chain of actin subunits; they bear tension and resist pulling forces within the cell; they form a 3-D network called the cortex to help support cells shape
Intermediate Filaments
support cell shape and fix organelles in place; more permanent then the other fibers
3 Extracellular Structures (outside the cell)
- Cell walls of plants
- Extracellular Matrix of animal cells
- Intercellular junctions
Plasmodesmata
channels that perforate plant cell walls; water and small solutes can pass from cell to cell
Intracellular Junction Types
- Plasmodesmata
- Tight Junction
- Desmosomes
- Gap Junctions
what do intracellular junctions do
neighboring cells in tissues, organs etc, often adhere, interact and communicate through direct physical contact; they facilitate contact
Extracellular Matrix of Animal Cells
animal cells lack cell walls but are covered by an elaborate extracellular matrix (ECM) on the surface
what is ECM made of
glycoproteins like collagen, proteoglycans, fibronectin
what do ECM proteins bind to in the plasma membrane
interns (receptor proteins)
Functions of the Extracellular matrix
support, adhesion, movement, regulation
