Fundamentals of Human Physiology Exam 1 UIOWA

Physiology

Study of human function

Homeostasis

Maintaining a stable internal environment to support optimal function under given circumstances

regulated variables of homeostasis

Blood pressure, pH, body temperature, blood sugar

Set point

value where we keep regulation in homeostasis

sensors (homeostasis)

detect changes in variables and relays to integrator

Integrator (homeostasis)

Makes decision what to do to regulate variables

effectors (homeostasis)

any organ or tissue that receives information from the integrating center and acts to bring about the changes needed to maintain homeostasis

Negative feedback system

a process that results in a response that reverses the original stimulus

Positive feedback system

strengthens or reinforces a change in one of the body's controlled conditions (not as common)

feedforward control

The anticipation of stimuli, activates effectors in advance (think sprinter before race, body starts to make changes to prepare for event)

levels of organization in the body

atomic

cell

tissue

organ

organ system

organism

Atomic/Molecular Level

all higher level functions are based upon the principles of physics and chemistry

cellular level of organization

basic unit of structure and function of living things

tissue level of organization

groups of similar cells that have a common function

organ level of organization

contains two or more types of tissues that form a structure with a specific function

organ system level of organization

Consist of different organs that work together closely to perform related functions

Organism level of organization

organ systems make up an organism

Four types of tissue

epithelial, connective, muscle, nervous

Muscle tissue

A body tissue that contracts or shortens, making body parts move.

types of muscle tissue

skeletal, cardiac (heart), smooth (organs)

Nervous tissue

Cells designed to receive and transmit information through neurons

Neurons

a nerve cell; the basic building block of the nervous system

Neuroglia

cells that support and protect neurons

epithelial tissue

A body tissue that covers the surfaces of the body, inside and out

- Functions: Regulates movement of materials, barrier, protection, form exocrine glands

Connective tissue

A body tissue that provides support for the body and connects all of its parts

Stem cells

unspecialized cells that retain the ability to become a wide variety of specialized cells

totipotent stem cells

Stem cells that can differentiate into ANY type of specialised cells found in organisms of that species.

pluripotent stem cells

Stem cells that can become almost all types of tissues and cells in the body but CAN'T form another organism

multipotent stem cells

stem cells that can become only one type of tissue and cell in the body

Body Fluid Compartments

intracellular and extracellular

intracellular fluid

fluid within cells

Extracellular fluid (interstital)

Fluid between cells

Extracellular fluid (Plasma)

plasma fluid

Chemical bond

the force that holds two atoms together by interaction of valence electrons

Molecule

two or more atoms held together by chemical bonds

nonpolar covalent bond

a covalent bond in which the electrons are shared equally by the two atoms

polar covalent bond

A covalent bond in which electrons are not shared equally

ionic bond

Formed when one or more electrons are transferred from one atom to another

Cation

Atom that loses an electron, becomes POSITIVE

Anion

atom that gains electrons, becomes NEGATIVE

Hydrogen bonds

Weak intermolecular attraction between polar molecules, the (-) of one polar molecule is attracted to the (+) end of another polar molecule

Acid

Release H+ when mixed with water

Bases

Gains H+ when mixed with water

Organic Macromolecules

carbohydrates

lipids

proteins

nucleic acids

Carbohydrates

the starches and sugars present in foods

major source of energy in body

categories of carbohydrates

monosaccharides, disaccharides, polysaccharides

Monosaccharides

- One carbon ring

- Basic unit

- Ex: glucose, fructose, galactose

Disaccharide

A double sugar, consisting of two monosaccharides

Polysaccharides

Carbohydrates that are made up of more than two monosaccharides

- Ex: glycogen, starch, fiber

Lipids

compounds that cannot mix with water

- Subclasses: triglycerides, phospholipids, steroids

Triglycerides

Stored form of energy in plants and animals

- Two types: saturated and unsaturated

Phospholipids

a lipid containing a phosphate group in its molecule instead of third fatty acid

phospholipid bilayer

A double layer of phospholipids that makes up plasma and organelle membranes

- Amphipathic

- Hydrophilic head

- Hydrophobic tail

Steroids

lipids characterized by a carbon skeleton consisting of four fused rings

- Ex: cholesterol, corticosteroids, sex steroids

Proteins

Chains of amino acids

amino acid structure

a carboxyl group, amine group, and R group

R group (side chain)

What group differentiates amino acids?

Polypeptide

A polymer (chain) of many amino acids linked together by peptide bonds

primary structure of protein

sequence of amino acids

secondary structure of protein

protein structure is formed by folding and twisting of amino acid chain

- due to hydrogen bonds forming between peptide bonds

tertiary structure

The third level of protein structure; the overall, three-dimensional shape of a polypeptide

- due to interactions of the R groups of the amino acids making up the chain

quaternary structure

The fourth level of protein structure; the shape resulting from the association of two or more polypeptide subunits

Glycoproteins

A protein with one or more covalently attached carbohydrates

Lipoproteins

protein + lipid

- Carrier molecules in blood

nucleic acids

DNA and RNA

Nucleic acid composition

five-carbon sugar, phosphate group, nitrogenous base

DNA

two strands linked together by hydrogen bonds

- Form double helix

- strands are complementary

- Recipe for proteins

RNA

single-stranded nucleic acid that contains the sugar ribose

ATP

(adenosine triphosphate) main energy source that cells use for most of their work

Microvilli

Fingerlike extensions of plasma membrane, increase surface area

Lysosomes

contains digestive enzymes

- Destroy: bacteria, old organelles, food molecules

Golgi apparatus

sorts and packages proteins made by ribosomes on rough ER

Gene

sequence of DNA that codes for a protein

Chromosomes

threadlike structures made of DNA molecules that contain the genes

Genome

All the genetic information in an organism; all of an organism's chromosomes.

Proteome

the entire set of proteins expressed by a given cell or group of cells

Transcription

synthesis of an RNA molecule from a DNA template

RNA polymerase

Separates the double-helix and creates a copy of one of the strands

Codons

A three-nucleotide sequence of DNA or mRNA that specifies a particular amino acid or termination signal; the basic unit of the genetic code

Splicing

the process of removing introns and reconnecting exons in a pre-mRNA

alternative splicing

regulated process during gene expression that results in a single gene coding for multiple proteins

Translation

the synthesis of a protein molecule from an mRNA strand

steps of translation

1. mRNA binds to a ribosome

2. Ribosome moves down mRNA looking for start codon

3. tRNA brings the appropriate amino acid into place

4. mRNA strand advances to next codon, where a new amino acid is brought in an peptide bond is formed

5. Continues as chain grows until a stop codon is reached

Hyperplasia

growth through cell multiplication

hypertrophy

growth through increase in cell size

Mitosis

Formation of two identical daughter cells from cell division following DNA synthesis

Meosis

Process by which two cell divisions produce haploid gametes

Necrosis

tissue death

Apoptosis

programmed cell death

lock and key model

The model of the enzyme that shows the substrate fitting perfectly into the active site

Metabolism

All of the chemical reactions that occur within an organism to maintain homeostasis

Anabolism

Requires the input of energy to synthesize molecules

Catabolism

Releases energy by breaking down molecules into smaller molecules

Macronutrients

______________________ are catabolized to release chemical energy

Glucose Catabolism

1. Glycolysis (always)

2. Citric Acid (krebs) cycle (IF O2 is present)

3. Electron transport chain (IF O2 IS PRESENT)

glycolysis

the breakdown of glucose by enzymes, releasing energy and pyruvic acid

- 2 pyruvate, 2 ATP, 2 NADH

Lactic Acid Pathway

- anaerobic conditions

- Pyruvic acid converted into lactic acid

- the process that occurs in absence of O2, cell must have an alternative pathway for pyruvate

The Krebs Cycle

second stage of aerobic cellular respiration, occurs in mitochondrial matrix

- pyruvate combines with coenzyme A to form Acetyl CoA

- then Acetyl CoA reacts to form 6 NADH, 2 ATP, 4 CO2

electron transport chain

A sequence of electron carrier molecules (membrane proteins) that shuttle electrons during the redox reactions that release energy used to make ATP

NAD+

In the electron transport chain, NADH produced from the krebs cycle is converted into _____________________