exam 1 BACKGROUND Flashcards
What is anatomy?
study of structure (detailed; look at structure, position, composition, & relation)
What is physiology?
study of function (how does this thing work?)
What are the levels of organization? (in order from smallest to largest)
chemical level, cellular level, tissue level, organ level, organ system level, & organismal level
What is the chemical level?
atoms that combine to form molecules & 3-D molecules (called macromolecules)
What is the cellular level?
organelles, atoms, ions, & molecules become organized into cells (some contain a nucleus)
What is an example of an organelle?
mitochondria; many macromolecules are also organelles
What is the tissue level?
similar cells from similar origins work together as a unit
What are the 4 types of tissues?
epithelial, connective, muscular, & nervous
What is the organ level?
2 or more tissues that work together for the same function
What is the organ system level?
2 or more organs that work together
What is the organismal level?
all of the systems working together
What is homeostasis?
the body “tries” to keep everything constant/regulated
What is matter?
anything that has mass and takes up space
What is mass?
amount of matter in an object (weight is the gravitational force on that mass)
What are elements?
the simplest type of matter made of identical particles called atoms
What are atoms?
basic building block of all matter; designated by an atomic number & composed of protons, neurons, and electrons
What is an atomic number?
the number of protons in the nucleus of an atom
What is atomic weight?
sum of the number of protons & neutrons in an atom (kind of)
Where are the protons, neutrons, & electrons located in an atom?
protons & neutrons are in the nucleus; electrons travel in the shell
What is the maximum number of electrons that the 1st shell can hold?
2 electrons
What is the maximum number of electrons that the 2nd & 3rd shells can hold?
8 electrons
When are atoms most stable?
when the outer shell is filled to the maximum (shells must be filled in order)
What do chemical bonds do?
transfer/share electrons between atoms so that the outer shells are filled to (or approach) the maximum; as a result, molecules are formed
What are the 2 types of chemical bond formations?
ionic bond formation & covalent bond formation
What is ionic bond formation?
when an electron moves from one atom to another, forming charged particles called ions
What is covalent bond formation?
a pair of electrons is shared; there are 2 different types
What are the 2 different types of covalent bond formations?
polar & non-polar
What is a non-polar covalent bond?
equal sharing of the electron pair
What is a polar covalent bond?
unequal sharing of the electron pair
What happens as a result of a polar covalent bond?
electrons are “pulled” in a way that causes 1 part of the molecule to gain a slight positive charge while the other parts become slightly negative
What are hydrogen bonds?
occur when areas of positive & negative adhere to each other (not a true chemical bond); these areas are weak associations between adjacent polar molecules; only formed by polar covalent bonds
What does hydrogen bond formation result in?
surface tension, capillary action, frost formation, & protein structure
What is an example of surface tension?
water spider walking on the surface; a paper clip floating in water
What is an example of capillary action?
pulling blood from finger prick; it is the movement of water due to forces
What is an example of frost formation?
snowflake structure; ice formation; results in frostbite
What is protein structure?
gives proteins a precise 3-D shape
What is organic chemistry based on?
the element carbon
What can carbon do to fill it’s outer shell?
bond with up to 4 atoms at a time
What are the 4 classes of biologic organic molecules?
carbohydrates, lipids, proteins, & nucleic acids
Which elements does carbon often form covalent bonds with?
hydrogen & oxygen; it can also covalently bond to nitrogen, phosphorus, sulfur, iron, & a host of other atoms
What are carbohydrates commonly called?
sugars & starches
What do carbohydrates contain?
carbon, hydrogen, & oxygen with the ratio 1:2:1; they have a chemical formula of (CH2O)n where “n” is the number of carbon atoms present
What do carbohydrate molecules do?
serve a structural purpose in our cells & are broken down to provide our cells with the energy required to carry out daily functions
How can carbohydrates be classified?
by their size & solubility (the ability of a substance to dissolve)
What are the 3 classes of carbohydrates?
monosaccharides, disaccharides, & polysaccharides
What are monosaccharides?
simple sugars such as glucose & fructose; they can be joined through a chemical reaction called dehydration to produce disaccharides
How are monosaccharides used?
as an energy source for our cells; these molecules are the most soluble
What are disaccharides?
formed when 2 monosaccharides are joined; they are present in many foods & include sugars such as sucrose and lactose
How are disaccharides used?
they are useful in energy generation when first dissembled through a chemical reaction called a hydrolysis reaction
What are polysaccharides?
formed when many monosaccharides are joined through a dehydration reaction; of all carbohydrate types, these molecules are the least soluble
How are polysaccharides used?
they are large molecules found as structural components in both plants & animals
What are the characteristics of polysaccharides in plants?
these molecules are called cellulose & are used to form plant cell structure; they make plant material “crunchy”
What are the characteristics of polysaccharides in animals?
these molecules are known as glycogen & are used as a storage form of energy
What are lipids?
non-polar molecules; they cannot mix well with polar molecules such as water; a chemical term used to describe these molecules is hydrophobic (water-fearing)
What are lipids made of?
long chains of carbon with hydrogen, oxygen, & often nitrogen and phosphorus
What are the 4 classes of lipids?
fats, phospholipids, prostaglandins, & steroids
What are fats used for?
these molecules serve as energy storage; they provide insulation & padding for delicate body organs
What are phospholipids?
unique hybrid molecules that contain 2 non-polar hydrophobic carbon chains (called “tails”) & 1 phosphate (PO4) molecule (called its “head”)
What portion of phospholipids are hydrophilic (water-loving)?
the “head” region of the molecule; it can easily mix with water
How are phospholipids used?
they are integral parts of cell membranes; this molecule forms an excellent barrier as it’s head end can mix with polar molecules like water while it’s tail end can only mix with non-polar substances
What are prostaglandins?
lipids that help the body respond to injury
How are prostaglandins used?
these molecules promote inflammatory responses throughout the body; they aid in blood clot formation & influence blood pressure
What are steroids?
these molecules are made of carbons arranged in 4 ring-like structures; they include many hormones & cholesterol; they are also present in cell membranes
What are proteins?
big molecules made of carbon, hydrogen, oxygen, nitrogen, & usually sulfur
How are proteins used?
these molecules are used as enzymes, energy sources, & structural components in the cell; they are made of subunits called amino acids
How are amino acids joined?
by using a type of covalent bond called a peptide bond
What causes “folding” in proteins?
the formation of hydrogen bonds between various areas of the protein due to the amino acid arrangement
What happens as a result of “folding”?
proteins have a very specific & often unique 3-D structure
What happens if the 3-D structure of a protein is altered?
the protein’s characteristics are usually altered as well
How can proteins be denatured?
by altering the pH of their environment, by heating them, or sometimes by exposing them to extreme cold
What are nucleic acids?
large molecules made of carbon, hydrogen, oxygen, nitrogen, & phosphorus arranged in units called nucleotides
How are nucleic acids used?
they form the genetic instructions that our cells use to manufacture proteins; we call these DNA & RNA
What is cytology?
cell biology
What 3 areas make up the cell?
cell/plasma membrane, organelles & cytoplasm, and nucleus
What is the cell membrane made of?
2 layers of phospholipids oriented tail-to-tail
What is the area inside of the cell called?
intracellular fluid/matrix (ICF)
What is the area outside of the cell called?
extracellular fluid/matrix (ECF)
What does the phospholipid bilayer do?
separates the ICF from the ECF, but it allows molecules to enter & exit; it is selectively permeable
What do cholesterol units do and where are they located?
they hold the phospholipids together to prevent unraveling; they are in the cell membrane between phospholipids
What structure is scattered throughout the cell membrane to act as a channel?
3-D proteins that come in different shapes/forms
What are branched carbs?
they are attached to some proteins & they serve as receptors/signals
What is cytoplasm?
mostly water in a semi-solid form that also contains ions & amino acids used to build proteins
What are examples of ions?
sodium (Na+), chlorine (Cl-), calcium (Ca++), potassium (K+), etc.
What are organelles & where are they found?
clumps of macromolecules where chemical reactions occur; found in the cytoplasm
What are examples of organelles?
mitochondria, ribosome, endoplasmic reticulum (ER), golgi body/apparatus, lysosome, etc.
What is the mitochondria?
capsular shaped (with folded inner membrane) that extracts ATP (cell energy) from glucose when oxygen is present
What are ribosomes?
2 subunit organelle with RNA between the subunits that assembles proteins from the intracellular amino acids
What is the endoplasmic reticulum?
a series of channels in 2 types: rough & smooth
What is the difference between the rough ER & smooth ER?
rough: has ribosomes attached & modifies newly formed proteins; smooth: no ribosomes attached & it manufactures specific lipids such as cholesterol
What is the golgi body/apparatus?
disc shaped; packages newly made proteins for export
What is the lysosome?
spherical structures that store molecules such as high-powered enzymes (called lysozymes)
What is the nucleus?
usually 1 centrally located structure; some cells have many or none
What is the nuclear membrane?
a double membrane that separates the nucleus from the rest of the cell; it fuses in spots to make nuclear pores so materials can pass in & out of nucleus
What is nucleoplasm?
cytoplasm that is within the nucleus
What are nucleoli?
dark regions in the nucleus where ribosomes are made
What are histone proteins?
structures that the DNA is wrapped around (like a spool of thread); DNA & RNA are housed in the nucleus
What is the cytoskeleton?
the proteins within the cell that act as a skeleton
What are the different parts of the cytoskeleton?
microfilament, intermediate fibers, thick filaments, & microtubule
What is the microfilament?
thin hair-like proteins that pass through the cytoplasm; it prevents the cell from tearing
What are the intermediate fibers?
thin proteins that have organelles & macromolecules attached; they move these items through the cytoplasm (like a clothes line)
What are the thick filaments?
thick proteins that enable cellular contraction
What are the microtubules?
tiny yet thick tubes that provide structure & a passageway for molecules
What is glycocalyx?
sticky carbs; membrane carbs are sticky & allow cells to adhere
What are desmosomes?
when cells membranes fuse in spots; these are abundant in cells that undergo mechanical stress (skin, muscles, uterus)
What is a gap junction?
when membranes of adjacent cells form passageways that hold cells together yet allow stuff to pass from one cell to the next
Where can gap junctions be found?
in heart muscle that forms intercalated disks; in embryonic tissues where connexons allow material to pass from cell to cell
What is a tight junction?
barrier substance that prevents materials from leaking between cells (in intestinal lining)
What is histology?
the study of tissues; there are only 4 types in the body
What is the epithelium?
covers body surfaces; lines hollow tubes, organs, & cavities; forms glands (sweat)
What is epithelium made of & how is it classified?
cells close together with only a little ECF between them; each cell has 1 centrally located nucleus; classified by cell shape & number of layers
Epithelium is avascular; what does this mean?
no blood vessels penetrate these tissues
What are the shapes of epithelial tissue?
squamous= flat & scale-like; cuboidal= box-shaped; columnar= rectangular and usually have a ciliates apical surface; transitional= variable shape that allows stretching
What is the apical surface?
the surface exposed to the environment
What is the basal surface?
the surface attached to what is underneath
What are the different layers of epithelial tissue?
simple= 1 cell layer thick; stratified= many cell layers thick; pseudostratified= 1 layer of cells that share the basal surface but are varying heights so it looks like multiple layers
What does “brush border” refer to?
the fuzzy appearance of cilia
What is connective tissue?
it connects body parts physically or physiologically; made of cells that are scattered apart in abundant extracellular matrix
What can the extracellular matrix be in connective tissue?
it can be liquid (blood), semi-solid (fat), slick (cartilage), or hard (bone)
Fibers of protein may be present in the matrix of connective tissue; what are these fibers like?
they may be parallel (ligaments), which gives strength; they may criss-cross forming a grid deep to the skin; they may be stretchy & made of elastin (tendons)
Do all types of connective tissues contain fibers?
no; many lack them & are very smooth
What is muscular tissue?
can respond to stimulus & contract, stretch, & return to its original state (recoil)
What are the 3 kinds of muscles?
skeletal, smooth, & cardiac
What are skeletal muscles?
made of cylinder shaped cells with many nuclei along the edges (peripheral located; multinucleate)
What are smooth muscles?
made of spindle shaped cells with one central nucleus per cell; located in the walls of hollow organs (stomach, bladder, uterus, etc.)
What is peristalsis?
occurs when smooth muscle contracts; contents of the organ are moved in a wavelike fashion
What is cardiac muscle?
found in the walls of the heart; made of branched interwoven cells for strength; joined together by lots of desmosomes & special gap junctions called intercalated disks that help coordinate contraction
What is nervous tissue?
made of cells called neurons that can generate, send, & respond to electrical stimuli & to chemicals called neurotransmitters
Which type of tissue provides one of our body’s major control mechanisms?
nervous tissue
