HHP-Module1

How many organ systems are there?

11

Homestasis aim

• keep humans healthy

• occurs across biological levels

• interaction between physiological, emotional, and environmental factors

Components of health

1. Disease

2. Risk factors

3. Physical fitness

4. Mental health

What makes humans different from other mammals?

• complex language

• culture

• future planning

• environmental interaction

What are physiological systems made of?

organs

What are organs made of?

tissues

What are tissues made of?

groups of similar cells

What do human cells contain?

membrane, cytoplasm, nucleus

What gives cell types their specific function?

cytoplasm

Most common cell type

RBCs

Organelles

subunit of the cell that performs specific function

Where are organelles and molecules?

inside cells

Molecule

a group of 2+ atoms

in situ

in place

in silico

in a computer

Theory vs. Hypothesis

theory: idea accepted by broader audience; not testable by single hypothesis; can be disproven but hasn’t yet

hypothesis: single part of scientific method, prediction about why an observation is occuring, not widely accepted, not supported by multiple experiments

Control

baseline for reference

Controlled environments

same temperature, food, water, lighting, genetic background, etc.

Negative control

group that doesn’t undergo experimental manipulation

Positive control

a known manipulation measured to show an expected result; used to test validity

Sham control

• type of negative control; inactive procedure designed to mimic active procedure

• controls for physiological responses due to traumatic events/ experiences

How to control for bias

Blinded control: participant or administrator is unaware of their group assignment

Double blind control: participant and administrator unaware of their group assignment

Standardized variables

things kept consistent between control & experimental groups

Do we prove or disprove things in science?

disprove

What drives physiological processes?

chemical reactions

Where do chemical reactions occur in humans?

water

Pure substance

contains only 1 type of atom

Atomic number

number of protons; never changes

Atomic mass

weighted average of all forms

Charge of atoms

net neutral

Do elements differ in number of protons, neutrons, or electrons?

neutrons

Isotopes

different forms of atoms from the same element

Charge of isotopes

net neutral charge

Doubly labelled water

form of isotope tracking, can be used to measure human energy expenditure

How isotopes have helped us understand physiology

• stable isotopes can be introduced to physiologically relevant molecules

• isotopes can be traced

Findings from isotope tracer studies

body is under a constant turnover of materials

Intermolecular bonds

• hydrogen bonds

• ion pairs

• hydrophobic interactions

Hydrogen bonds

between hydrogen atom of a polar covalent intramolecular bond and another electronegative atom

Ion pair

general electrostatic interactions between opposite charges

Why are hydrophobic interactions biologically important?

• protein folding

• lipid bilayer

• digestion of dietary lipids by bile

Polypeptide; Protein AA

polypeptide less than 50 AA; proteins more than 50 AA

Functions of proteins

support, enzymes, transport, defense, hormones, motion/force, energy

Activation energy

minimum amount of energy needed for a chemical reaction to occur

Tertiary protein structure

• R-group interactions

• single peptide chain

• hydrophobic inside; hydrophilic inside

Intrinsically disordered protein

• highly dynamic & charged

• no stable 2 prime structure

Where are proteins in our cells

in water

Brownian motion

random movement of particles in water

Organic molecules + examples

primarily made of carbon; proteins, carbs, nucleic acids, lipids

Monosaccharide examples

glucose, fructose, galactose

Isomers

molecules with same atoms but different arrangement of the atoms

Why is glucose important

• metabolism

• common

• stable

• circulates blood

Disaccharides

formed by dehydration reaction

Disaccharide examples

glucose + glucose = maltose

glucose + fructose = sucrose

glucose + galactose = lactose

Oligosaccharides

between simple sugars & polysaccharides (3-10 monomers)

• can join with proteins to make glycoproteins (cell markers)

Polysaccharide

hundreds of monomers joined together

Polysaccharides in humans

• glycogen for storage mainly in liver & muscle

• muscle breaks down for energy and liver breaks down to regulate blood sugar

4 categories of lipids

1. triglycerides

2. phospholipids

3. steroids

4. waxes

Triglycerides

• 3 long hydrocarbon chains (fatty acids)

• bond to glycerol (backbone)

Saturated fatty acid

• no c-c double bonds in fatty acid chains

• hydrocarbon chains are straight, and stack

• solid at room temperature

Why is is called a “saturated” fatty acid?

all carbon molecules are bound to the maximum amount of hydrogen atoms possible

Unsaturated fatty acids

• at least one c-c bond (mono/polyunsaturated)

• not able to stack due to double bond

• liquid at room temperature

Why is it called an “unsaturated” fatty acid?

carbon atoms do not have maximum amount of hydrogen bound

Trans fats

• manipulated by hydrogen bonds surrounding to make stackable

• makes unsaturated fatty acids solid at room temperature

• not recognized by the body

• artificial

Waxes

forms fatty acid chains with alcohol

Strong acids

complete dissociation (ionization) in solutions

Weak acids

partial dissociation; some hydrogen remain bound

Strong bases

complete dissociation; releases hydroxide ion

Weak bases

partial dissociation

Buffer systems + Ex.

weak acids and based that resist pH changes; regulates pH change in body Ex. bicarbonate buffer system

Acids

substances that release hydrogen ions when in water

Bases

substances that accept hydrogen ions/ release hydroxide ions when in water

pH regulators

buffer systems & membrane bound transporters

Fluorophore

chemical compound that emits light

What underlying cellular events can pH changes indicate?

apoptosis

Cytoplasm pH during apoptosis

decreases

Genome

all genetic information in a cell

is DNA a right or left handed helix?

right handed helix

Sugar in DNA

5 carbon deoxyribose sugar

DNA backbone

sugar-phosphate backbone covalently bonded by nucleic acids

tRNA

• mRNA-AA adapter

• binds to AA and codon on mRNA