Final Exam Review: Unit 1

anatomy definition

the study of form

physiology definition

the study of function

levels of complexity and examples

chemical (Na, Cl)

cells (nerve, keratinocytes)- first level to contain life

tissues (blood, bone)

organ (heart, brain

organ system (integumentary, digestive)

organism

what is homeostasis

the ability to maintain a stable internal environment despite changing external conditions

what are the characteristics of homeostasis

variables fluctuate around set points (to reach dynamic equilibrium), as the boy responds to stressors. the goal is to reach balance. (set point = average set of values for any given variable)

what are the components of feedback loops (with examples)

receptors: monitor variables in body and send information to ICC (chemoreceptor and thermoreceptor)

Integrating control center: receives and processes information, determines and sends response to effectors (cardiac center of brain, endocrine system, hormones as communication molecules)

effectors: carry out corrective action (heart, uterus)

negative feedback loop definition 

mechanism for opposing and reversing change within the body. pushes variables closer to set point, and closer to equilibrium

positive feedback loop definition

mechanism that pushes the body away from homeostasis by reinforcing changes. pushes variables further outside of set point

what are the benefits and drawbacks of positive feedback loops

they allow the quick completion of stressful events, but they cause the body to be pushed further from the life sustaining state of homeostasis

what is an example of a positive feedback loop

the uterus contracts, the baby’s head hits the cervix and stretch receptors trigger the release of oxytocin, which causes the uterus to contract again

what is an example of a negative feedback loop

person rises from bed, blood pressure drops, baroreceptors sense change, the cardiac center releases norepinephrine to raise heart rate, the increased HR raises BP

what is a plane

an imaginary flat surface through the body or an organwh

what is the frontal plane

runs along the body’s length, dividing anterior and posterior

what is the sagittal plane

runs along the length of the body, separating left and right

• paramedian is a sagittal plane that divides unequally

• median plane is a sagittal plane that divides equally

what is the transverse plane

perpendicular to frontal and sagittal, divides the body into superior and anterior

• oblique is a transverse plane that divides the body at an angle

What causes the formation of hydrogen bonds? Characteristics, what are they responsible for?

negative oxygen is attracted to partially positive hydrogen.

• these are the weakest bonds individually, and they cant form molecules.

• they can change molecule shape, which is responsible for the shape of water molecules

components of atoms

• protons (within nucleus, positive)

• neutrons (within nucleus, neutral)

  • electrons (orbiting nucleus, negative)

what is the importance of electrons to chemical stability

electrons orbit the nucleus in energy levels; the outermost level is called the valence. atoms with full valence shells can not form chemical bonds and are considered stable and inerty. Atoms with vacancies in their valence shells are reactive and able to form bonds.

what are ionic bonds

bonds formed between atoms where one atom gives electrons and becomes a cation (1-3 valence electrons), and one receives electrons and becomes an anion (4-7 valence electrons). 

what are covalent bonds

bonds formed when atoms share electrons.

• polar covalent bonds are when electrons are shared unequally, so there is a difference in charges across the molecule

• nonpolar covalent bonds are when electrons are shared equally

  • (the equality of sharing is determined by the electronegativity of elements involved)

rank the types of bonds from strongest to weakest

nonpolar covalent, polar covalent, ionic, hydrogen

kinetic energy- definition, example

energy of motion, moving muscles

potential energy- definition, example

energy of position, chemical energy stored in food

properties of enzymes

reusable (never consumed or changed by reactions), specific (matched for a specific substrate), have saturation limits (when all enzymes are working, the solution has reached saturation), regulated (can be turned off by adding inhibitor to active site), capable of denaturation (can lose shape and function with extreme pH, temperature) and require cofactors (they can be regulated by requiring a cofactor- non protein partner- to work)

what is the function of enzymes

they act as biological catalysts, lowering the activation energy required for reactions to begin within the body by increasing the rate of the reaction.

properties of water

polar, adhesive, cohesive, chemically reactive, thermally stable, solvency, v-shaped

what substances would dissolve in water

ionic and polar compounds

would nonpolar compounds dissolve in water

no

would phospholipids dissolve in water

no. they are amphipathic and have water-loving parts and water-hating parts, so they would not entirely dissolve.

definition of acid

substance that dissolves in water to produce hydrogen ions. these are proton donors.

definition of base

substance that absorbs free hydrogen ions when added to water, forming hydroxide ions. These are proton acceptors.

what is an organic molecule

one containing carbon and hydrogen

• covalent bonds

• large, complex

what is an inorganic molecule

a molecule that does not usually contain a carbon, and if it does, the carbon is not bound to hydrogen

• covalent or ionic bonds

• water, O2, CO2

what are the monomers or carbohydrates

monosaccharides

what are the monomers of proteins

amino acids

what are the monomers of nucleic acids

nucleotides

what are the functions of carbs. examples of carbs in the cell and in the body

source of short term/easy access energy

examples in the body are forming ribose and deoxyribose, forming glucose, and stored as fat/glycogen

what is are the functions of proteins. examples on the cell and within the body

• structure: components of cells and tissues

• communication: hormones, receptors

• membrane transport: form channels

• catalysts: enzymes

• protection: glycoproteins are identity molecules for body cells

• movement: motor proteins

  • cell adhesion: bind cells to each other

in the cell, receptors and channels and glycoproteins

in the body, enzymes, hormones, antibodies

what are the functions of lipids. examples in the cell and within the body

• energy sources: in adipose tissue

• storage

• structural components

• communication: hormones and local signaling molecules

in the cell as the phospholipid membrane.

in the body as hormones (steroids) and prostaglandins

what can changes in pH cause

can disrupt the physiology of body systems, denature enzymes, and alter drug reactions.

what does the pH scale indicate (how is pH measured)

the relative level of hydrogen ions in a solution. bases have lower values, acids have higher values.

what are the three basic components of eukaryotic cells

the nucleus, cytoplasm, and plasma membrane

what are the components of the plasma membrane

lipids: majority of membrane molecules, phospholipids form the semipermeable bilayer and regulate material exchange. cholesterol regulates membrane fluidity. glycolipids form glycocalyx, which has roles in cell ID

proteins: integral proteins are fixed in place, and peripheral proteins are easily separated from the membrane. act as receptors to bind ligands, enzymes to catalyze reactions, and cell ID markers for immunity

carbs

what substances can cross the plasma membrane

small, nonpolar substances

active membrane transport

includes primary and secondary active transport. moves up gradient and requires energy.

• primary active transport moves substances up their concentration gradient, examples are Na/K pumps and calcium pumps. requires carriers.

  • secondary active transport indirectly requires ATP. diffuses substance down its gradient, and moves a second substance along with the first substance. the concentration gradient of the first substance is maintained by primary active transport, which requires ATP. examples are sodium-glucose transporters. requires carriers.

passive membrane transport

includes simple diffusion, osmosis, filtration, and facilitated diffusion. moves down gradient, no energy required

• simple diffusion is movement of particles from high to low concentration. moves small nonpolar substances (alcohol, steroids, water, gasses) 

• facilitated diffusion is movement from high to low concentration that is carrier mediated, moving glucose, water, amino acids, and ions. requires carriers.

• osmosis is movement of water from low solute to high solute concentration

• filtration is when physical pressure forces fluid through selectively permeable membranes. done in kidneys and capillaries. moves fluid and small particles across membrane.

isotonic solutions

concentration of solute inside cell equals that outside cell, causing no movement of water. no change in cell volume.

hypertonic solutions

concentration of solute is greater outside cell than inside, so water exists cell and cell volume decreases. can lead to crenation.

hypotonic solutions

concentration of solute is greater inside cell than outside cell, so water enters the cell and cell volume increases, potentially causing lysis