BIOL 2160- LSU EXAM 1

Physiology

Function, Form dictations function, how a molecule is shaped determine the job that is does.

Anatomy

Structure

Physiological Organization

Molecules, Cells, Tissue, Organs, Organ Systems

Organ System Examples

Cardiovascular, Gastrointestinal

Organ Examples

heart, liver

Tissue Examples

Nervous tissue, muscle tissue

Cells Examples

Neurons, Epithelial Cells

Molecules Examples

ATP, water, neurotransmitter receptors

Neurons/Nervous Tissue

Specialized for sending and receiving information (motor neurons, cortical interneurons, etc)

Muscle Cells/ Muscle Tissue

Specialized for contraction, must contract to survive

Smooth Muscle cells

only found in the heart

Epithelial cells/ epithelial tissue

found on organs, glands, and lining body cavities (mouth, nose, ears, etc)

used for exchange

makes up the boundary between one area and another

makes up most of the skin

Endocrine Glands

Secrete molecules, (usually hormones) directly into the blood stream. i.e. pancreatic and thymus glands

• secrete into a capillary (bloodstream)

Exocrine Glands

Utilize a duct. secrete molecules into a body cavity, or to the exterior of the body. i.e. stomach, salivary, seat glands

Connective tissue cells

Characterized by very few cells and lots of extracellular materials (water, salts, and proteins)

ex: bone cells, blood cells, fat cells, fibroblasts, bone cartilage, tendons, and ligaments

Homeostasis

Ability to maintain a relatively stable internal environment despite fluctuations in the external environment; essential for survival and function of all cells

What does deviation from homeostasis indicate?

Disease

How is homeostasis most often accomplished?

Negative feedback

Negative Feedback

Involves returning internal conditions to a "set point"

Negative Feedback Loop

Helps return internal conditions to a set point when they deviate too far outside of an acceptable range. Input and Outpoint are opposites.

What is an example of the negative feedback loop?

Shivering when you get cold

Negative Feedback Sensors

In the body, detects change and sends information to the integrating

• found in skin

Negative Feedback Integrating Center

Assesses change around a set point; the integrating center then sends instructions to effector

• usually not the brain, but not always

Negative Feedback Effector

Makes appropriate adjustments to try and return the body to its set point

• the sweat glands; take orders from the integrating center

Regulated variable

Any internal condition that must be monitored and maintained within the system, "normal levels"

Example of negative feedback

Increase in glucose induces a decrease in glucose, returns system to set point

insulin and glucagon

these are antagonistic effectors; a hormone that lowers your blood sugar and a hormone that raises your blood sugar

Why do people shiver with fever?

Fever is physiological response, involves changing body temperature, set point has changed

Antagonistic Effectors

these do the exact opposite of each other, but work together to keep conditions stable

• homeostasis is often maintained by these that move conditions in opposite directions

• maintains dynamic constancy; conditions within a certain normal range

Positive Feedback

Moves conditions further away from a set point. The input and the output in a positive feedback loop are the SAME.

Positive Feed example

uterine contractions during child birth; release of oxytocin causes the uterus to contract and this pushes the baby’s head against the cervix, activating stretch receptors that signal to the hypothalamus; resulting in more oxytocin release, which results in stronger contractions

Atom

basic smallest unit of all forms of matter; retains the physical and chemical properties of the element

• everything living/nonliving is made of this

• made up of subatomic particles (neutrons, protons, and electrons

Electron Orbitals

3-D space around the nucleus of an atom where an electron will be found

Chemical behavior of atom

Determined by the number of electrons in the outermost electron shell

Reactive

Atom with incomplete electron shell is ______

Inert, not chemically active

Atom with full electron shell is ____

(found on far right column on periodic table)

how does a reactive atom fill its valence shell?

Will try to fill vacancy or get rid of extra electrons so outer shell is full by interacting with other atoms which may result in two atoms forming a chemical bond

Chemical bond

Attraction that holds two atoms together; happens because of 2 or more elements are trying to fill up their outer electron orbital

Molecule

Two or more atoms held together by chemical bonds; smallest unit that retains the physical and chemical properties of a compoound

When does an ion form?

When an atom has an almost empty or a almost full outer electron shell

What is an anion?

Negatively charged atom or molecule, it gained an electron (more electron than protons)

What is a cation?

Positively charged atom or molecule, it has lost an electron (more protons than electrons)

Covalent Bond

Formed when two atoms share pairs of electrons

Nonpolar Covalent Bond

electrons spend equal time near each nucleus, covalent bond in which the sharing of the electron pair is EQUAL, same charge on both nuclei

Polar Covalent Bond

Covalent bond in which the sharing of the electron pair is UNEQUAL, electrons spend more time near the larger nucleus

Electronegativity

atom's ability to attract and hold electrons. Indication of how much positive charge is in the nucleus. assigned a numerical value. the higher the number, the more electronegative an atom is

What happens to atoms with higher electronegativity?

Atoms with higher electronegativity have more positively charged nucleus, holds onto electron pair more strongly than atoms with significantly lower electronegativity

2.2

Hydrogen EV

2.6

Carbon EV

3.0

Nitrogen EV

What bonds are atoms next to each other compared to atoms separate by one?

Non-polar compared to polar

Hydrogen Bond

Formed by the charge attraction when a (H) hydrogen atom which is covalently bonded to one atom is attracted is attracted to a second atom

polar covalent bond

bond between hydrogen and oxygen in a SINGLE water molecule is a ______

hydrogen bond

bond between hydrogen and oxygen in SEPARATE water molecules is a _____

strong

polar covalent bonds are _____

Hydrophilic

Describes property of having an affinity for water

What hydrophilic substances easily dissolve in water?

Polar and ionic

hydrophobic

nonpolar substances

describes the property of NOT having an affinity for water

Why do hydrophobic molecules clump together in water?

Because of hydrophobic interaction

Why doesn't oil dissolve in water?

The non polar oil molecules cannot form hydrogen bonds with the polar water molecules

in-depth: oil doesn’t have a charge and for something to dissolve in water, it has to form hydrogen bonds with water, hence the charge

What are the four basic types of biomolecules?

Carbohydrates, Lipids, Proteins and Nucleotides

Carbohydrates

Monosaccharides that contain carbon, hydrogen, and oxygen in a 1:2:1 ratio, ring structure, amin purposes: short-term energy

What is glycogen?

Energy storage molecules in humans, used for quick energy and is metabolized when blood sugar levels drop

Where is glycogen stored?

Skeletal muscle and liver of humans

when blood glucose levels are high → short term energy and depleted within a week

Carb-loading

Process of increasing the amount of glycogen stored in the body prior to a race or competition

(think of michael phelps)

What is the depletion phase in carb-loading?

A week or two prior to competition, intense exercise and a no-carb/ high protein diet

What is the loading phase in carb-loading?

A couple of days before competition, no intense exercise, eating as many carbs as you can take in

How is fat burned in human body?

Blood glucose is metabolized first. Afterwards, glycogen reserves are metabolized…then fat

Why does glycogen dissolve in water?

It is polar. Each ounce of glycogen has as many as four ounces of water attached to it

(think of water weight)

What is fat?

Non polar, it has no water attached to it

What are lipids?

Usually hydrophobic (insoluble in water) and consist of non polar hydrocarbon chains and rings

What is a saturated fat?

Solid at body temperature. they have no C=C bonds. they are saturated with hydrogens (lard, grease, fat)

What is an unsaturated fat?

Liquid at body temperature, have at least one C=C bond. (Olive Oil, Vegetable Oil)

• healthier; liquids in the bloodstream are less likely to clog arteries

What fat is less likely to clog arteries based on consistency?

Unsaturated fat-Not very dense when moving through body

chewy

cookies that have lots of saturated fats are ____

crunchy

cookies that have unsaturated fats are ______

Phospholipids

Two fatty acids and phosphate groups attacked to glycerol backbone, are dominant component of cell membranes, and contain hydrophilic (polar) and hydrophobic (nonpolar) regions

Phospholipid Bilayer

Hydrophilic head, phobic tails i.e. laundry detergent (polar and non-polar)

Steroids

Three 6 carbon and one 5 carbon rings, mostly nonpolar, many function as HORMONES (estrogen, testosterone, cholesterol) 98% of the time its 4 rings

Proteins

Composed of multiple amino acids (amino acid polymers)

sequence of amino acids is determined by DNA through processes of transcription and translation (gene expression)

Amino Acid

Composed of an amino group, a carboxyl group, and a functional group or R group (sidechain)

What does 20 R groups mean?

20 different amino acids

What do the R groups give amino acids?

Different properties such as polar and non polar

primary, secondary, tertiary, and quaternary

levels of protein structure

what structure do all proteins have and what do they sometimes have?

always primary secondary, and tertiary; sometimes quaternary

Primary Structure

Amino acid sequence

Secondary Structure

Every twist, fold, helix, topographical feature in the protein

Tertiary Structure

3D shape of protein; function; protein folded up as whole

Quaternary Structure

Chain of amino acid to peptide to several proteins stuck together

Nucleotides

Composed of a 5-carbon sugar, one or more phosphate groups and a nitrogenous base

What 2 categories do the nitrogenous bases fall into?

Pyrimidine and Purine

What is pyrimidine?

One carbon ring, Cytosine ( C ) and Thymine ( T ) in DNA

What is purine?

TWO carbon rings, Guanine (G) and Adenine (A) in DNA

What are the possible bases?

Pyrimidines- C,T,U

Purines- A, G

what is the difference between DNA and RNA?

5 carbon sugar

in DNA, sugar is deoxyribose

in RNA, sugar is ribose

DNA Structures

AT and GC, TA and CG- Sugar phosphate backbones, and complementary base pairings

Gene

Length of DNA that codes for a specific protein

Gene Expression

Converting DNA into proteins (transcription and translation)

What is Transcription?

DNA -> RNA, occurs in nucleus

happens first; think of a book you check out, but can make a copy of it

What is Translation?

RNA -> protein, occurs in cytoplasm on the ribosome