Physiology study guide Exam 1 (ch 1-3)

The Study of Body Function 

Physiology 

• The study of biological function, i.e how the body works 

• Various  levels: molecular/cellular, tissues. organs , system s, organism 

• Mechanisms

• Cause and effect 

• Information is obtained via scientific method, hypothesis-driven experimentation and testing 

The Hierarchy of Living Systems 

• Cells: the fundamental unit 

• Tissues: groups of same cell type 

• Organs: multiple tissue with a common function 

• Organs System: multiple organs 

• Organism: multiple organ systems 

Organ Systems  

• Circulatory/Cardiovascular: heart and vessels

• Respiratory: lungs and air passageways

• Digestive/Gastrointestinal: digestive tract, glands

• Urinary/Renal: kidneys , bladder

• Musculoskeletal: muscles, tendons, bones

• Immunes: white blood cells, spleen 

• Nervous: brain, spinal cord, sensory organs

• Endocrine: pituitary gland, thyroid glands, ect.

• Reproductive: ovaries, uterus, testes 

• Integumentary: skin 

Homeostasis: A Framework for Human Physiology 

• Homeostasis: state of relative constancy of the internal environment

  • it is maintained via negative feedback loops 

  • Examples of physiological variables kept relatively constant by homeostasis: body temperature, sodium, glucose, pH oxygen 

Homeostasis and Negative feedback 

• Changes in a physiological variable are detected by a sensor 

• Information is sent to an integrating center, which causes an effector to produce a change in the opposite direction. This is an example of negative feedback. The variable returns to its set point via homeostasis 

• Negative feedback: An increase or decrease in a variable causes a response to move the variable in the direction opposite the original change 

• Dynamic constancy: fluctuating around a set point.

• Maintenance of body temperature: Shivering is a response to decreed in temperature, while sweating is a response to increase in temperature

Primary Tissues 

Muscle: for contraction 

Nervous: for generation and conduction of electrical event, and related support functions

Epithelial: forms membranes covering & lining body surfaces, or glands comprised of these membranes

Connective: characterized by large amount of extracellular material; connective tissue proper, blood, bone, cartilage (outside of the cells)

Ch2 

Chemical Composition of the body 

Ions 

• An Ion results when an atom gains or loses one or more electrons. 

  • Ions are mismatched in the number of protons and electrons 

• An ions proton-electron mismatch is indicated by the sign(plus or minus) and number of signs 

  • CI- (gained an electron)              

  • Ca++ (lost two electrons)

Strength and Type of Chemical Bonds and interactions (Strongest- Weakest)

• Covalent bonds (atoms share electrons) 

  • e.g., methane, Ch4

• Ionic bonds (opposite charges attract) 

  • e.g., sodium chloride, Na+CI- 

• Hydrogen bonds (electrostatic attraction of H to O or N) 

  • e.g., between H2O molecules 

• Van der Waals forces (weak local forces) 

  • e.g., between lipid molecules

Solvent + Solute(s) = A Chemical Solution

Chemical concentration  

• The amount of solute present in a given volume of solvent 

The Molecular weight (MV)

• Number of grams of that solute you would need to add to a liter (L) of solvent to produce 1-molar (M) solution 

Solubility 

• Polar compounds (atoms at each end of bond have opposite charge 

• Non-polar (atoms at each end of bond have same charge\

• Hydrophilic “water loving” compounds 

• Hydrophobic or “water fearing compounds do not dissolve unless submerged  up

• Amphipathic “dislike both: compounds are hydrophophilic and a hydrophilic 

  • Forme clusters when mixed with water

The pH value indicates the acidity 

pH = -log[H*]

• High pH is alkaline

• Low pH is acidic 

Organic Molecules 

• Contain C and H 

• 4 types:

  • Carbohydrates

  • Lipids

  • Protein 

  • Nucleic acids

Carbohydrates 

• Structure

  • Sugars and starches

  • Contain: C, H, O

  • Usually hydroxyl (OH) group linked to C

  • CnH2nOn

  • Covalent bonds

• Function 

  • Energy storage and production 

• Sucrose (table sugar) 

  • Disaccharide 

  • Linked of Glucose and Fructose 

    • Loss of water(dehydration)

Lipids 

• Structure

  • Fatty acids, triglycerides, phospholipids, steroids

  • H, C

  • Nonpolar covalent bonds (low solubility in water)

• Function 

  • Best energy source

  • Membranes, hormones

  •  Insulation

• Glycerol and fatty acids are subunits for the formation of Triglycerides,  and phospholipids(membrane components)

• Phospholipids are formed from glycerol, two fatty acids, and one or more charged groups 

• Micelles (aggregates of molecules) form when phospholipids, which are amphipathic, mix in water 

  • Group together so that their polar, hydrophilic regions face the surrounding (pair) water molecules 

• Cholesterol molecules (steroid)

  • Promote membrane fluidity and serve as starting materials for the synthesis of steroid hormones 

Proteins

Structure:

• Polymers based on amino acid monomers

• Macromolecules with thousands of atoms

• Levels of structure

• Carbon, hydrogen, oxygen, nitrogen, sulfur + other elements in small amounts

• Various bonds, created via dehydration 

Function:

• Enzymes, cell attachment, cytoskeleton, muscle contraction, hormones 

Amino acids 

• Contain(s) amino group, carboxyl group, and side R chain

Peptide bonds are covalent bonds that connect neighboring acids together to form a polypeptide(chain of amino acids)

Levels of structure:

Primary:

• Amino acid sequence 

Secondary 

• DOlded, twisted shape j

• Hydrogen bonds

TertiaryL 

• Two or more protein s at the tertiary level stuck together

• Many parts 

Nucleotides/Nucleic Acid

Structure

• Sugar + Base + Phosphate

• Various types of bond

• Repeating subunits in chain 

Function 

• Information storage (DNA and RNA, nucleic acids)

• Energy storage (ATP, nucleotide)

• High energy e-transfer molecules (coenzymes, nucleotides 

  • NADH FADH2

• DNA is deoxyribonucleic 

  • Contains instructions for protein synthesis

• Acid and RNA is ribonucleic acid

Bases

• Cytosine

  • w/ Guanine

• Guanine

  • w/ cytosine

• Adesine

  • w/ thymine or uracil 

• Thymine

  • w/ adesine 

CH 3

Structure of the cell 

• Cell is the basic human unit of  structure and function 

• Structure determines function

• Components 

• Membranes  internal and external partitions 

• nucleus : contains genomic DNA

• Cytoplasm: aqueous content of cell inside membrane 

• Ribosomes: protein reticulum protein synthesis, calcium dynamics 

• Golgi apparatus: Secreted proteins 

• Mitochondria: ATP synthesis 

Plasma Membrane 

• pLasma membrane with each cell

• Double phospholipid can invest 

• Separates internal cellular structures from extracellular environment

• Selectively permeable 

• allows communication and exchange

Types of Membrane Protein 

• Intrafloral 

  • Bound to molecules in the membrane

  • Trans membrane

  • Can cross lipid bilayer

Cytoskeleton 

• Network engineer, full of interconnect microtubules 

Protein synthesis 

• Many functions in the body 

• Cell signaling, membrane receptors enzymes, ion channel, cell attachment, cytoskeleton

• Large molecules more than 100

• 20 amino acids

Splicing

• Cutting molecule an folding back together

• Non-coding regions are called introls while coding regions are called exons

• Protein Synthesis: process

In nucleus 

• DNA has information for synthesis from protein 

• Genetic Transcription

• Splicing removes introns and splices exons

• Resulting in mRNA exits nucleus and entrance cytoplasm

Ribosome

• mRNA binds to ribosome

• Genetic Translation

Protein synthesis 

• In the polypeptide chain, the amino acids innerwear to create its secondary structure 

• Then it folds and bends to create its tertiary structure 

• Synthesized proteins are either used within the cell or secreted by the cell to a different destination 

• Proteins to be secreted are sorted in the Golgo apparatus, based on function and destination 

• Proteins to be secreted are packaged into vesicles in the Golgo apparatus before secretion