BIOL120 Lec Exam 1

Skeletal system functions

Hemopoiesis (blood cell synthesis)

Muscular system functions

Locomotion, maintaining posture, thermogenesis; 44%

Nervous system functions

Monitors internal + external env, necessarily responding by initiating muscular/glandular activity

Endocrine system structures

Hypothalamus, pituitary, thyroid, thymus, pineal. parathyroid, adrenal, pancreas, small intestine, stomach, testes, ovaries, kidneys, heart

Endocrine system function

long-term control system; regulates growth, reproduction, nutrient use

Lymphatic and immune system structures

Lymphatic vessels, lymph nodes, spleen, thymus, red bone marrow

Lymphatic and immune system function

Returns “leaked” fluid back to bloodstream, dispose debris, attack foreign invaders

Respiratory system structures

Nasal cavity, pharynx, trachea, bronchi, lungs

Respiratory system functions

Supply O2 into blood, take out CO2, regulate blood pH

Urinary system function

Regulate water, electrolytes, and acidity levels

Conditions for homeostasis

1. Proper concentrations of gas, nutrient ions, water

2. Optimal temp

3. Optimal volume for cell health

Extracellular fluids (ECFs)

1. Surround the cells (interstitial, intercellular/cellular fluids)

2. Circulate in blood cells (plasma) or lymphatic vessels (lymph)

Examples of external stimuli/stress

Heat, cold, loud noises, lack of oxygen

Internal stimuli/stress

Low blood glucose, increased ECF acidity

Feedback components

Control center, receptor (afferent), effector (efferent)

Negative feedback

Reverses original stimulus; self-terminating

• Increase in body temp → receptors → brain → sweat glands + skin’s blood vessels dilate → body temp goes down

• Increase in blood pressure

Positive feedback

Enhances original stimulus; ended by outside factor

• Uterus is stretched → uterus’ sensitive neurons are stretched → nerve pulses to hypothalamus → release oxytocin → uterus contracts more forcefully

Bilirubin

Brown-yellow bile pigment secreted by liver in vertebrates

• High levels during pancreatic cancer or disease bc of blocked bile duct from a tumor

Digital subtraction angiography (DSA)

After contrasting dye is injected into blood vessel (aorta)

• Good for studying blood vessels in brain and heart

Positron emission tomography (PET)

Radioactive substance is injected into the body + gives colored image; info on function, structure

• Good in detected heart or brain’s metabolic changes

Chemical level

Essential atoms (C, O, H, Ca, N)

• Can combine to form molecules like proteins, carbs, lipids

Tissue level; types

Arise from same ancestor and collaborate in same function

• Epithelial (protective + glandular). connective, muscular (movement), nervous

System level

2 or more organs collab in common function (ex. cardiovascular system)

Atomic weight is

Sum of protons, neutrons, and electrons

Atomic number

# of protons in atom’s nucleus

Mass #

# of protons and neutrons

Isotopes

Atoms of elements w/ same # of protons but diff # of protons

Radioisotopes

Unstable isotopes

Catabolism

Bonds are cut apart and release energy

Anabolism

Bonds form and consumes energy

Van Der Waals forces

Hold nonpolar molecules together

Chemical reactions depend on

Concentration of particles, speed, activation energy, proper orientation

Acids

Ionize into H+ and one or more anions

Bases

Ionize into OH- and one or more cations

Molarity

moles/liter = molar = M

Types of functional groups

Carbs, lipids, proteins, nucleic acids, ATP

Carbohydrate functions (2-3% of body weight)

• Provide energy (ATP)

• Food reserve (glycogen)

• Create bulk (cellulose)

Carbohydrate major groups

Monosaccharides, disaccharides, polysaccharides

Monosaccharides

3-7 carbon atoms, simple sugars

• Trioses, pentoses, hexoses

Disaccharides

Formed by two monosaccharides thru dehydration synthesis

Glycogen

Store glucose polymer, mostly in skeletal muscle + liver cells

Carbohydrates in clinical applications

Oligosaccharides on RBC, in plasma (blood), agglutination (process when person receives wrong blood w/ wrong antibody)

Lactose

Broken down by lactase enzyme

Galactosemia

Genetic defect that makes infant unable to utilize galactose (part of milk)

• Can accumulate in system and lead to mental retardation, growth failure, cataract formation

Polysaccharides function

Used as fillers (inactive ingredients in drugs) bc of their solubility in water and thickening/gelling properties

Hyaluronic acid

Acidic polysaccharide, abundant in eyeball (vitreous fluid + collagen/protein)

• Acid can form liquid pockets in eyeball → retina detachment/blindness

Lipid properties (18-25% of body weight)

• Hydrophobic (insoluble in polar solvents) bc they have fewer polar covalent bonds

• Most lipids combine w/ proteins → lipoproteins for blood transport

Lipid major groups

Triglycerides, phospholipids, steroids

• Sphingolipids (coat nerve axons/myelin sheath), eicosanoids, carotenes (yellow-orange pigments for vision)

Prostaglandins

Formed from eicosanoids, “local hormones” that contribute to inflammatory response, dilate lung airways, regulate body temp

Leukotrienes

Participate in allergic + inflammatory reactions

Triglycerides (most abundant lipids in body) function

Store polymer for fatty acids/neutral fat; protection, insulation, energy

Saturated fatty acids (solid @ RT)

• Single covalent bonds

• Palmitic + stearic acids

• Coconut and palm oil

Monounsaturated fatty acids (solid @ RT)

• One double covalent bond

• Oleic acid, olive and peanut oil

Polyunsaturated fatty acids (liquid @ RT)

Linoleic acid, corn oil

Atherosclerosis

Artery vessels are narrowed bc of cholesterol; too many saturated fats are consumed

Trans fats

Produced by adding H atoms to unsaturated plant oils/partially hydrogenated oils

Phospholipids

Have glycerol backbone

• Head: glycerol, phosphate group, charged group

• Tail: two fatty acids

Steroids

Nonpolar, four-ring hydrocarbon structure (steroid nucleus)

Precursor for all other steroids

Cholestrol

Protein functions (12-18% of body weight)

• Function as enzymes

• Structural roles (keratin)

• Movement (motors, kinesin and dynein)

• Body’s defenses (antibodies)

• Fuel (amino acids)

• Transporting substances (hemoglobin)

Protein makeup

Polymers of (20 diff) amino acids

• Amino group + carboxyl group

• Linked by peptide bonds into polypeptides

Peptides are formed by

Two or more amino acids linked by peptide bonds from dehydration synthesis

The different protein structures are

• Primary (amino acid comp)

• Secondary (hydrogen bonds; alpha helix, beta sheet)

• Tertiary (hydrogen, ionic, covalent bonds)

• Quaternary (More than 1 polypeptide)

Sickle anemia is and happens in

Valine (np) substitutes glutamic acid (p) at position 6; hemoglobin is insoluble + forms crystals in red blood cell → sickle cells that affect O2 transport

• Happens in primary structure

Secondary structure is held together by

Hydrogen bonds

Denaturation is; examples

Stress → loss of protein’s characteristic shape + function

• Albumin: white of egg is transparent when properly folded but turns white when boiled

• 70% ethanol: denatures and kills bacteria; good for disinfecting

Enzymes speed up chemical reactions by

• Increasing collision freq

• Lowering activation energy

• Properly orienting colliding molecules

Holoenzyme is made out of

• Apoenzyme (protein portion)

• Co-factor (non-protein like metal ions, vitamins)

Enzyme application examples

Meat tenderizers (papain) and penicillin that inhibits transpeptidases

What does ATP (adenosine triphosphate) do

Transfers energy from chemical bonds to endergonic (energy absorbing) reactions within cell

How is energy stored in ATP

In covalent bonds between the phosphates

Nucleic acids

Huge organic molecules w/ C, H, O, N, P

Types of nucleic acids

DNA (genetic code, double helix) and RNA (protein synthesis, single strand)

Examples of purines (double ringed nitrogenous bases)

Adenine and Guanine (AG)

Examples of pyrimidines (one ring nitrogenous bases)

Cytosine, Thymine (DNA only), Uracil (RNA only)

• CTU

What are nucleotides made of

Base + sugar + phosphate group

What are nucleosides made of

Base + sugar

Chargaff’s rule

• Adenine must pair w/ thymine

• Guanine must pair w/ cytosine

DNA and RNA differences

• DNA has sugar deoxyribose

• RNA has uracil, DNA has thymine

Major types of RNA

• mRNA (messenger, travels from nucleus to ribosomes)

• rRNA (ribosomal assembly and function)

• tRNA (transfer, brings AA to ribosome for peptide bond formation + protein synthesis)

What is the plasma membrane composed of

• Phospholipid bilayer (75%)

• Glycolipids (5%): cell adhesion

• Cholesterol (20%): steroid to strengthen membrane but reduces flexibility

Types of membrane proteins

• Transmembrane (integral): extend across fatty acid tails, nearly all glycoproteins (proteins w/ sugar)

• Peripheral: loosely attached to inner + outer surface membranes

Membrane protein functions

• Channels with pores

• Transport substances from one side to the other

• Can bind to proteins at cell surface to convey message if substances don’t enter cell

• Enzymes

• Cytoskeletal anchors: attach cytoskeletal filaments to plasma membrane

• Cell identity markers (for ABO blood types and RBC)

Membrane structure

Plasma membrane is mosaic of proteins floating like icebergs in a sea of lipids

Glycocalyx

External fuzzy coat w/ carbs linked to lipids + proteins unique for each indiv

Passive transport meaning + types

Depends on kinetic energy; higher to LOWER concentrations

• Filtration, simple diffusion, facilitated diffusion, osmosis

Active transport meaning + types

Requires atp since movement is independent from concentration gradient; lower to HIGHER concentrations

• Active and vesicular transport

Adenosine triphosphate (ATP) composition

Adenine (base) + ribose (five c sugar, pentose)

• Manufactured from ADP + phosphate group + energy

• Hydrolyzed by ATPases (adding water molecule)

What is the catabolism of glucose

Cellular respiration

ATP functions

• Energy storing, transferring from exergonic to endergonic reactions '

• Provides energy for activities like muscular contraction, synthesis reactions

• Cyanite inhibits ATP production, shutting off active transport

How does filtration work

Moves along membrane/capillary wall from gravity OR hydrostatic pressure

Where does simple diffusion happen + when does net diffusion stop

Happens across lipid bilayer, stops when EQUILIBRIUM is reached

What does simple diffusion depend on

• Concentration gradient

• Temp (higher → faster)

• Size

• Lipid solubility (hydrophobic diffuses thru plasma membrane, hydrophilic needs protein channels)

• Membrane surface area

• Diffusion distance/thickness

How does facilitated diffusion work

W/ transporter or channel BUT doesn’t req potential energy

How does glucose movement work

Glucose is too lipid soluble to move by diffusion so it uses glucose transporter molecules

• Phosphate group attached to glucose by hexokinase once inside → glucose 6-phosphate

• Insulin: facilitates glucose transport thru transporter molecules

• Moves in intestine’s epithelial cells AGAINST glucose’s concentration gradient

• Symport cotransport w/ usually Na+ ion can be used to move glucose in animal cells

What are aquaporins

Integral membrane proteins that function as water channels to assist water movement during osmosis

What is osmotic pressure and what does it depend on

Pressure that moves water thru selectively permeable membrane; depends on concentration of non-permeable particles in solution

• Higher concentration of nonpermeable → higher osmotic pressure

What does osmosis assist in

• Moving water betw. diff body compartments

• Maintaining cell volume constant

Osmosis in clinical applications

Edema: osmotic pressure in blood is higher than pressure in interstitial fluid that bathes cells

• Blood’s osmotic pressure is lowered → water moves at greater rate into interstitial space, causes swelling

Hypotonic solution

Water concentration > impermeable particles, water moves INTO rbc

• Hemolysis → RBC bursts