Unit 1 Test Review

homeostasis

how body regulated its own internal environment

negative feedback

Reverses change in the controlled condition

Is mad that it is happening

Regulates conditions that are usually stable

Ex: when body temp drops, we shiver to produce heat.

positive feedback

enhances change in the controlled condition

happy that it's happening

reinforces circumstances that don't happen often

ex: contractions get worse with time during childbirth

Afferent pathway

carries info from sensory neurons to the control center (the brain)

Efferent pathway

takes the info from the control center (the brain) out to the effectors (muscles, organs, systems)

effectors

body structure (organ or cell) receives the output from the brain and creates a response that changes the controlled condition.

receptor

monitors changes in controlled conditions and sends input to the brain if something is off.

cranial cavity

the brain

pericardial cavity

the heart

pleural cavity

the lungs

abdominal cavity

all the digestive organs: the stomach, both the s/lg intestines, liver, spleen, gallbladder, pancreas, uterus, Fallopian tubes, ovaries, kidneys, ureters, bladder.

vertebral cavity

the spinal cord

pelvic cavity

the internal reproductive organs: the bladder, rectum, colon (uterus, Fallopian tubes, and ovaries for females)

Sagittal plane

longitudinal plane that divides the body or organ into right and left sides

median plane (midsagittal)

body or organ is divided into equal right and left sides

paramedian plane (parasagittal)

sagittal plane that divides the body or organ into unequal right and left sides.

coronal plane (longitudinal)

divides the body or organ into anterior (front) and posterior (back) portions.

transverse plane (cross-sectional or horizontal)

horizontal plane that divides the body or organ into upper and lower portions.

oblique plane

passes through the body or organ at an oblique angle.

superior

above

inferior

below

lateral

side

medial

middle

proximal

ONLY TO REFER TO ARMS AND LEGS
nearest the trunk or the point of origin of a part.

distal

ONLY TO REFER TO THE ARMS AND LEGS
farthest from the trunk or the point of origin of a part.

What are the major elements in the body? They make up how much of the body's mass?

Oxygen, Carbon, Hydrogen, and Nitrogen

They make up 96% of the body's mass

What are the lesser elements in the body? They make up how much of the body's mass?

Calcium, Phosphorus, Potassium, Sulfur, Sodium, Chlorine, Magnesium, and Iron

They make up 3.6% of the body's mass

What are trace elements? How many of them are there and how much of the body's mass do they make up?

They're present in tiny amounts. There are 14 of them and make up about .4% of the body's mass

Isotope

atoms of an element with the same atomic number but with different numbers of neutrons which changes their mass numbers.

Cation

Positively charged ion

Anion

Negatively charged ion

Electrolyte

An ionic compound that breaks apart into positive and negative ions in a solution.

Covalent bonds

Two or more atoms share electrons instead of gaining or losing them.

Single covalent bond

Two atoms share one electron pair (2 electrons)

Double covalent bond

When atoms share 2 pairs of electrons (4 electrons)

Triple covalent bond

When atoms share 3 pairs of electrons (6 electrons)

Energy

The capacity to do work

Metabolism

The sum of all chemical reactions in the body

Endergonic reactions

Require energy - they absorb more energy than they release

Exergonic reactions

Release energy - they release more energy than they absorb

Synthesis reactions

When 2 or more atoms, ions, or molecules combine to form new and larger molecules.

Catabolism

Breakdown of complex substances into smaller, simpler components

Exchange reactions

When both synthesis and decomposition happen

AB + CD --> AD +BC

Reversible reactions

The products can go back to the original reactants

Inorganic compounds

Usually lack carbon and a have a simple structure

Organic compounds

Always have carbon and usually have hydrogen. Always have covalent bonds.

Hydrolysis

a chemical reaction in which water is needed to break down molecules

Dehydration synthesis reaction

When 2 smaller molecules combine to form a larger molecule, a water molecule is one of the products.

Hydrophilic

dissolves easily in water (likes water)

Hydrophobic

not very soluble in water (fears water)

Steroids

have 4 rings of carbon atoms

Body can synthesize steroids from cholesterol which has a large non polar region

What are sterols? list them

have at least 1 hydroxyl group (OH)

cholesterol, estrogen, testosterone, cortisol, bile salts, vitamin D.

Enzymes

Catalyst made of proteins (speeds up reactions). Some are made of 2 parts.

Characteristics of enzymes

Enzymes are highly specific: each particular enzyme binds only to specific substrates (the reactant molecules that the enzyme helps)

Enzymes are very efficient: they catalyze reactions from 100M-10Bx faster than those that happen w/o enzymes

Enzymes are subject to a variety of cellular controls: the cell's genes control the rate of their synthesis and concentration

Enzymes lower the activation energy of chemical reactions: they decrease the "randomness" of the collisions between molecules and orient so the reaction happens

What are the 3 main parts of a cell?

plasma membrane, cytoplasm, and nucleus

What is the lipid bilayer made up of?

2 layers back-to-back

made up of 3 types of lipid molecules: phospholipids, cholesterol, and glycolipids.

What is the polar part of the lipid bilayer?

polar "head" that is hydrophilic. This part faces the extracellular fluid or the cytoplasm

What is the non polar part of the lipid bilayer?

2 long fatty acid "tails" that are hydrophobic. This part is found between the "heads"

Integral proteins

extend into or through the lipid bilayer and are firmly embedded. They are amphipathic

How are integral proteins attached to the lipid bilayer?

by covalent bonding to the fatty acid tails.

Transmembrane proteins

span the entire lipid bilayer and go into both the cytosol and extracellular fluid.

Peripheral proteins

not as firmly embedded in the membrane

What are peripheral proteins attached to?

polar heads of membrane lipids or to integral proteins.

Ion channels

pores or holes that let specific ions like potassium to flow through to get in or out the cell.

Carriers

select which polar substances to move from one side of the membrane to the other.

Receptors

(cellular recognition sites) each type of receptor recognizes and binds to a specific type of molecule (ligand).

ligand

a specific molecule that binds to a receptor

Enzymes

catalyze (speed up) specific chemical reactions both inside and outside of the cell.

Linkers

integral proteins that attach the plasma membrane to neighboring cells.

Cell identity markers

enable a cell to recognize other cells of the same kind during tissue formation

recognize and respond to potentially dangerous foreign cells.

Permeable

structure lets the passage of a substance through it

Impermeable

structure does not let the passage of substances through it.

Selective permeability

structure lets some substances to pass through while not letting others through.

What substances is the lipid bilayer highly permeable to?

oxygen, carbon dioxide, and steroids.

What substances is the lipid bilayer moderately permeable to?

small uncharged molecules like water and urea

What substances is the lipid bilayer impermeable to?

ions and large, uncharged molecules like glucose

Transmembrane proteins

act as channels and increase membrane permeability to ions.

Diffusion

Random mixing of particles in a solution that happens because of kinetic energy.

What factors influence diffusion rates?

1. steepness of the concentration gradient
2. temperature
3. mass of the diffusing substance
4. surface area
5. diffusion distance
(check slides for explanations)

Isotonic solution

1. solute concentration equal on both sides of cell
2. water concentration equal on both sides
3. no net movement of water
4. cell size stays the same

Hypotonic solution

1. solute concentration is higher inside the cell (water goes IN the cell)
2. water concentration is higher outside the cell
3. net movement from outside of cell INTO the cell
4. cell will swell (cell may burst open)

Hypertonic solution

1. solute concentration is high outside the cell (water LEAVES the cell)
2. water concentration is higher inside the cell
3. net movement from inside of cell to OUTSIDE of cell
4. cell will shrink

Primary active transport

Energy from hydrolysis of ATP changes the shape of carrier proteins to "pump" substances across the plasma membrane against the concentration gradient.

Secondary active transport

The energy stored in a Na+ or H+ concentration gradient is used to drive other substances across the membrane against their own concentration gradient.

Vesicle

small spherical sac that transports substances from one structure to another

Endocytosis

materials move into a cell through a vesicle formed from the plasma membrane.

required ATP b/c they're active processes

Exocytosis

materials move out of a cell by fusing with the plasma membrane.

required ATP b/c they're active processes

Cytoskeleton

a network of protein filaments that extends through the cytosol.

has microfilaments (microvillus), intermediate filaments, and microtubules (cilia, flagella)

Rough endoplasmic reticulum (ER)

Protein synthesis

Smooth ER

synthesizes fatty acids and steroids

stores calcium in muscle

Golgi complex

matures and modified proteins for their specific functions

Lysosomes

recycle worn-out organelles

digest chemical compounds

Peroxisomes

destroy superoxide

Proteasomes

destroy unneeded, faulty, or damaged proteins

Mitochondria

creates ATP and contains DNA only from the mother.

Nucleus

contains the cell's DNA

What are the stages of cell division?

interphase, prophase, metaphase, anaphase, and telophase.

Interphase

cell replicates DNA and produces additional organelles

Prophase

Chromatin fibers condense and shorten into chromosomes

Metaphase

microtubules of the mitotic spindle align the centromeres of chromatid pairs.