Gen Bio Exam #1 (Not mine - I imported andressa221's set)

What are the three types of memory?

Sensory, short term, long term

CC types of memory

Sensory: holds memory for a couple of secs

Short term: memory held in a maximum of 7 slots in the brain. In other words, anywhere from a seconds to minutes. Info gets released if irrelevant.

Long term: memory held in for a lifetime. Info is retained and there is unlimited storage/duration. Can be retrieved into STM when needed.

What is LTP?

Long lasting increase in synaptic strength.

SEQ LTP

1. Short term memory gets encoded into long-term memory

2. That memory is also retrieved through practice

3. Through retrieval, changes occur in chemical synapses (LTP) where the long term memory has formed and can be retrieved whenever.

Once LTP is completed....

There are more NTs (neurotransmitters), receptors, pre synaptic axon terminals and the action potential starts faster.

LTM is formed by....

encoding

What is encoding?

-Converting info into a format that can be stored

-Important for LTP

What is memory?

-Physiological (normal occurrence) event happening at synapses

-Neuronal activity and plasticity

What is learning?

-Ability to recall info and make use of it in practical circumstances

-Use of memory to decrease likelihood of negative outcome

-To learn you must be active and organized

CC memory and learning

Memory- comes before learning

Learning- the use of memory to do better

Memory does NOT equal learning

To know about the brain...

1. Embryonic development occurs

2. Has many neurons

3. Neuronal plasticity occurs

What is neuronal plasticity?

-The ability of neural networks to change

-In other words, your brain reorganizes as a result of experience and learning

What are synapses?

Junctions between neurons

Your brain is very....

Activity dependent!

Use it or lose it!!!

What are the goals of workshop?

1. Improve ability to organize material- form memories

2. Use memories to learn and problem solve

3. Prep for higher level questions- MCAT + other exams

Overview of workshop

-40% of overall course grade

-Mandatory

-TA facilitates student activities

-Students work w/ lecture content

-Students will use chunking (organize and associate notes)

-Works with lecture content

Glucose Homeostasis/Diabetes example

1. Stimulus: Blood glucose is too high

2. The beta cells in your pancreas release insulin (hormone)

3. Insulin goes into your muscle in liver cells.

4. In the LIVER, the glucose gets stored into glycogen

5. Muscle and liver cells react at the same time, lowering the blood glucose

6. Your body reaches homeostasis (balance)

7. Now your blood glucose is too low (new stimulus)

8. The alpha cells in your pancreas releases glucagon (hormone)

9. Glucagon goes to muscle and liver cells

10. In the LIVER, the glycogen makes glucose (more sugar yay!)

11. Muscle and liver cells react at the same time, raising the blood glucose).

12. Body reaches homeostasis and process starts all over again...

What is emergence?

-The whole is more than the sum of its parts

1. Emergent properties result from arrangement and interaction of parts within a system

2. Properties of life emerge at different levels

Levels of Biological Organization

Biosphere

Ecosystems

Communities

Populations

Organisms

Organs + organ systems

Tissues

Cells

Organelles

Molecules

What is reductionism?

Reduction of complex systems to simpler components that are more manageable to study.

Ex: studying DNA

What is evolution?

-The process of change that has transformed life on Earth

-Explains the unity and diversity of organisms

What are the three domains?

Bacteria

Archaea

Eukarya

Science

"To know"

Natural cause for natural phenomena

Systematic experimentationn (observations and measurements)

SEQ Scientific Method

1. Observation/Problem

2. Background info

3. Hypothesis (not a theory)

4. Experiment

5. Analyze results (statistics)

6. Report/revise/repeat/verify

CC hypothesis and prediction

Hypothesis: an educated guess.

Prediction: If/then statement derived from the hypothesis. Predictions are tested.

If no evidence supports a hypothesis,

then it is false.

If the prediction is not wrong,

do not reject the hypothesis.

If the prediction is wrong,

reject the hypothesis and revise.

Electrons

-Negatively charged particles

-Found on shells (distanced from neurons)

-Has potential energy (E) aka the potential to do WORK

Energy levels of an atoms electrons

-The 1st shell has the LOWEST E

-When enough E is absorbed, an electron moves to the 2nd shell and then the 3rd and so on

-When E is released, the electron moves back to the 1st shell

Valence Shells

-The outermost shell

-H and He are full with 2 valence electrons

-All other atoms are full with 8 valence electrons

-Involved w/ chemical rxns

What are molecules?

-Two or more atoms combined in a fixed ratio

-They are joined by chemical bonds

What is a chemical formula?

-Types of atoms

-Shows the ratio of elements in a compound aka how many of each atom

-Ex: H2O; 2 Hydrogens, 1 Oxygen

What is a chemical equation?

-Description/representation of a chemical rxn

-Reactants -> Products

Participate yields formed

-Ex: 2H2 + O2 -> 2H2O (balanced equation)

What is electronegativity?

-The ability of an atom to attract electrons

-X (fancy X) Chi

-Increased amount of X pulls electrons stronger to itself aka the greater the electronegativity, the stronger an electron is pulled towards an atom

What are the different types of chemical bonds?

Covalent bonds; Nonpolar covalent and polar covalent

Ionic bonds

Hydrogen bonds

What are covalent bonds?

-Shares a pair of electrons

-Each atom has filled valence shell

-Strong bond

What are non-polar covalent bonds?

-Little to no difference in electronegativity

-Electrons are shared EQUALLY

-Ex: O2, CH4,

What are polar covalent bonds?

-Difference in electronegativity is less than 2

-Electrons are shared UNEQUALLY

-Electrons spend more time around the more electronegative atom

-One end is partial positive and the other is partial neg.

-Ex: H2O

Oxygen is more electronegative so electrons spend more time with O than with H. Therefore H is partial POSITIVE and O is partial NEGATIVE

What are ionic bonds?

-Difference in electronegativity is greater than 2

-Electrons are CAPTURED/TRANSFERRED to another atom

-Forms ions aka atoms that are electrically charged

-Ionic bonds are SALTS

-Very strong bonds

-Become very weak in H2O because they are hydrophilic (dissolve in water)

What are Hydrogen bonds?

-Very weak bonds BETWEEN two molecules (not within)

-H atom is partial positive so it is attracted to partial negative atoms (other oxygens)

-Ex: H2O

Each H2O can H bond with 2 other H2O molecules

Constantly broken and reformed in liquid H2O

Weaker than covalent bonds

Collectively strong

Van Der Waals Interactions

-Nonpolar molecules

Electrically neutral

Electrons are in constant motion; temporary regions of weak charge

Excess of electrons= negative charge

Deficit of electrons= positive charge

-Adjacent molecules interact

-Short distances

-Weak

What are the emergent properties of water?

1. Cohesion

2. Adhesion

3. Moderates temperature

4. Expansion Upon freezing

5. Solvent

What is cohesion?

-Water sticks to itself

Ex: Surface tension

H bond to each other and molecules below

"Film" on surface

What is adhesion?

-Water sticks to something else

Ex: Capillary action

H2O rises in small spaces of hydrophilic (water loving) material... like a paper towel soaking up liquid

Combo of cohesion and adhesion

Moderates temperature..

-Prevents extremes...

-High specific head

Lots of heat enegy breaks H bonds and increases temp of H2O

-High heat of vaporization

Lots of heat to convert liquid to gas

Evaporative cooling or sweat

Expansion upon freezing of water

-Liquid

about 15% of H2O molecules are bonded to 4 others

many are close

-Ice (0 degrees)

100% of the molecules are bonded to 4 others

move apart which leads to more expansion

Why should we care?

Ice is less dense than liquid H2O so it floats. This is important for when a pond freezes over... the ice should remain at the top instead of the bottom so it doesn't disrupt any life.

Solvent

Dissolves a solute

Hydrophilic substances

-Many regions of partial positive and negative

-Forms H bonds with H2O -> dissolve

-Polar and charged

Hydrophobic substances

-Does not form H bonds

Does not dissolve

-Nonionic/nonpolar and uncharged

Ex: Oils

Carbon

-Has 4 valence electrons

-Can form up to 4 covalent bonds

-Has the ability to form complex organic compounds

-Linked to C, H, N, or O

Cell

-70-90% H2O

-Rest is mostly carbon based compounds

Hydrocarbons

-Only C and H

Ex: Methane; CH4

-Hydrophobic

-Nonpolar covalent linkages

C skeletons can vary by...

1. length

2. double bond position

3. branching

4. rings

Functional groups

-Replace the H on skeleton

Ex: CH4 ——> CH3OH

CH3 is the R group. OH is the functional group!

-Determines molecular behavior

What are the 7 important functional groups?

Hydroxyl, Methyl, Carbonyl, Carboxyl, Amino, Sulfhydrl, Phosphate

Hydroxyl

R-OH or -OH

-Polar (electronegative O)

-Alcohol

Ex: Ethanol

Methyl

CH3 or RCH3

-Non-polar ( C and H have similar electronegativity)

Ex: 5 Methyl-Cytosine

Carbonyl

-Aldehyde = terminal

-Ketone = internal

-Polar (electronegative O)

Carboxyl

O=C-OH or -COOH

-Charged

-Two O's very close

-Acts as an acid (H+ donor)

-Carboxylic acid

-Components of amino + fatty acids

Amino

NH2 or H-N-H

-Charged

-Acts as a base (H+ acceptor)

-Amines

Acids

Donates H+ (protons)

Bases

Accepts H+ (protons)

Sulfhydrl

-SH

-Polar

-Form disulfide bonds in proteins

Phosphate

Pi or PO4 3-

-Charged

-Phospholipids and nucleic acids

Macromolecules

-1000s of atoms

-4 classes in cells: carbs, lipids, proteins, nucleic acids

-polymers

-polymer synthesis and breakdown

-not all macromolecules are polymers !!

Polymers

Macromolecules produced by linking monomers (chain like)

Polymer synthesis and breakdown

-Dehydration synthesis: synthesizing (putting it together) a polymer

Hydrolase

H2O molecule added and bond broken

Ex: short polymer + unlinked monomer = longer polymer

-Hydrolysis: breaking down a polymer

Ex: longer polymer = short polymer + unlinked monomer

Which macromolecules are polymers?

carbs, proteins, nucleic acids

Which macromolecules are not polymers?

lipids

Carbohydrates

-CH2O

-end in "ose"

Monosaccharides

-Simple sugars

-monomers —> build complex carbs

•3-7C

•OH groups

•Carbonyl group (aldehyde or ketone)

-Very hydrophilic

Ex: ribose and glucose (aldehyde sugar)

Dissacharides

-2 monosaccharides bonded together

-Dehydration synthesis

•Glycosidic linkage (covalent bond)

-Ex: sucrose

Polysaccharides

-Polymer

-100s-1000s sugars

-various functions

Storage function of a polymer

-Food reserves (source of E)

-Starch

•only in plants

•alpha glucose subunits

-Glycogen

•only in animals

•alpha glucose

•large and highly branched

•stored in liver and muscles

Structural function of a polymer

-Strength

-Cellulose

•plant cell wall

•Beta glucose

•Difficult to hydrolyze (break down)

Ex: Fiber

-Chitin

•Arthropods and fungi

•Beta glucose and N group

Lipids

-Not polymers

-Nonpolar (hydrophobic)

-Greasy and oily

-Does not dissolve in polar solvents (H2O)

-Dissolves in nonpolar solvents (chloroform)

Fats

-Most abundant lipid

-E storage

1g fat = 9 cal of E

1g carbs/protein = 4 cals of E

-Consists of glycerol (3C alcohol) and 1, 2, or 3 fatty acids

-Saturated and unsaturated FA

-Triacylgycerols

Saturated FA

-Each C is completely associated with a H

-Solid at room temperature

-Animals fats (butter)

Unsaturated FA

-H removed —> Double bond between C's

-Bends —> prevents close packing

-Liquid (oils) at room temp

-Plant and fish fat

Triacylglycerols

-Triglycerides

-Main storage form of fat

-Glycerol and 3 fatty acids —> 3x dehydration synthesis —> 3 molecules H2O released. Ester linkages (covalent bonds)

Ester linkages

The bonds that join the glycerol to the fatty acids

Phospholipids

-Glycerol is attached to phosphate and 2 fatty acids

-R group is attached to phosphate

-Amphipathic (hydrophilic and hydrophobic portion)

-Plasma membrane (PM)

Steroids

-C skeleton: 4 fused rings

Ex: Cholesterol

•Found in animals

•Synthesized in liver

•PM

•NOT in plants

Isomers

Different structures with same molecular formula

Amino acids

-Monomers of proteins

-20 aa

-has fundamental structures

Polypeptides

Around 100 to 300 aa

Heterotrophs (1st)

-Organic molecules from the environment that eats other organisms for E

-Fermentation (anaerobic -no O2- breakdown)

Nucleic acids

-Polymers made up of nucleotides (monomers)

Nucleotides are linked by covalent bonds

-DNA and RNA

-Transmit hereditary information and determine polypeptides produced by a cell

Montmorillonite

-Soft clay from volcanic ash

-Early earth

-Ions catalyze vesicle formation

Geological time scale

-Divisions

-Rocks and fossils

Photosynthetic autotrophs (2nd)

-E from sunlight to produce food from simple inorganic molecules

-Cyanobacteria

O2 revolution (rapid increase of atmospheric O2 around 2.4 billion years ago)

How many structures do proteins have?

Four (Primary, Secondary, Tertiary, and Quaternary)

Endosymbiotic Theory

-How euk. cells arse from prok.

-In primary symbiosis, a prok. was engulfed

- ^Mutual and obligate relationship between host and endosymbiont

-Until around 1.7 billion years ago, only single celled prok and euk existed

Formation of protocells

Vesicles form, isolate organic molecules within a membrane

Tertiary Structure

-One polypeptide chain

-Various bonds between R groups

-Complex 3D shape

Abiotic Structures of organic molecules

-Clay/Rock surfaces

Zn2+ and Fe2+ (bind monomers)

-Lab

Drip aa solution on hot rocks --> polypeptides

Secondary Structure

-H bonds between close aa's

-No R groups

Multicellular eukaryotes

-1.7 bya: microscopic

-600mya: large, soft bodied, diverse

-535-525mya: cambrian explosion (rapid evol. of animals)

-500mya: Colonization of land (plants, fungi, and land animals)

Protein

-A 3D polymer made of monomers of amino acids.

-3D confirmation (shape)