Gen Bio 115: Midterm one

Nervous System

consists of circuits of neurons (communicative cells) + supporting cells. It is developed during embryonic development

Synapses

junctions between neurons; changes depending on activity

Neuronal Plasticity

ability to grow and can be modified after birth; can be remodeled to suit the changes at synapses

ex. dynamic changes/more receptors & transmitters when LTP is developed

“Use it or Lose it”

the more you use a stimulus, the more connections are made to it. This allows for long term memory to be made.

Multiple Active synapses

mutually reinforced stronger synapses

ex. memory is triggered by the connections between multiple active synapses

Short Term Memory

info stored for short time release if irrelevant; Stimulus goes into the short term memory creating temporary synapses

Long Term Memory

saved stimulus or when info is retained needs to be retrieved into the STM 

learning

use of knowledge/experience (memory) to decrease likelihood of negative outcomes

memory

is what you retain and learning is what you do based on that 

Long term Potentiation

Lasting increase in the strength of synaptic transmission - physiological changes at synapses that makes communication easier (facilitates retrieval)

chunking

learning sets of related information rather than just one thing at a time: helps with retrieval; rhythm 

What happens to synapses after LTP

 you have multiple receptors when you encode a memory enough making it easier for you to recall the memory 

Evolution

Unifying idea of bio all living organisms are modified descendants of common ancestors (helps answer questions about biological processes)

Emergent Properties

 properties that can be found through the arrangement and interaction of parts within a system. It’s the arrangement of the parts that help you communicate an idea. 

Hypothesis

Educated guess; testable

Prediction

Expected outcome when you test hypothesis

CC Theory vs Law

Theory: Broad explanatory idea that has a lot of support, leads to new hypothesis and accurate predictions

Laws: Statement of a what always occurs under circumstances; descriptive idea

electrons

negative subatomic charge

potential energy

material that processes E due to its location or structure

What is the connection between electrons and energy?

electrons have E due to distance from the nucleus; further from the nucleus → higher energy; closer to the nucleus → less energy

molecules

a compound of two or more atoms held together by a chemical bond

What is the purpose of a chemical formula?

it tells what and how many atoms there are

Chemical bonds

Result of how atoms share electrons, stabilize the valence shell

electronegativity

measure of an atoms affinity to electrons

how do you know if something is more electronegative?

there is a stronger pull of electrons or they have more protons

ex. oxygen is highly electronegative

Covalent Bonds (strongest BIOLOGICAL conditions)

sharing electrons between atoms

non polar covalent bonds

electrons shared equally

polar covalent bonds

electrons shared unequally

Ionic Bonds

• electrons is lost or gained

• highly unequal electronegativity

• intramolecular

• acidic

ion

charged molecule

Anion

negatively charged (more electrons than protons)

Cation

positively charged (more protons than electrons)

Van der Waals Interactions

• relatively short lived weak interactions

• areas with partial + and - charges interact

Hydrogen bonds

partial charges result when a hydrogen binds to negative atoms (like Oxygen or Nitrogen)

POLAR due to the bond between a positive and negative atom

Which bonds are intermolecular and which are intramolecular

Intermolecular: Hydrogen

Intramolecular: Ionic and Covalent

Cohesion

water sticks together

ex. surface tension

Adhesion

water sticks to other things

ex. capillary action (tendency to rise against gravity)

What are the Properties of Water?

• regulate temperature

• expand when frozen (crystalline structure prevents bodies of water from freezing solidly from the bottom)

• hydrophilic v. hydrophobic

What type of bonds can hydrophilic substances form with water?

they can form hydrogen bonds

Carbon can form…

4 bonds

oxygen can form…

2 bonds

Hydrocarbon

organic molecules of only carbon or hydrogen

• nonpolar

• uncharged

ex. methane

functional groups are

specific groups of atoms responsible for a characteristic of that molecule

Functional groups and hydrocarbons

if a function groups is used, it is no longer a hydrocarbon

functional groups can replace

hydrogen

Hydroxyl (-OH)

Oxygen bound to hydrogen

• polar

• hydrophilic

ex. alcohol

Carbonyl (=O)

carbon with a double covalent bond to Oxygen

• polar

• hydrophilic

Carboxyl (-COOH)

carbon with double bond to one oxygen and a single bond to an OH

• acidic (lose proton)

• polar

• hydrophilic

Amino (-NH2)

nitrogen with 2 hydrogens, proton (H+ acceptor)

• basic (accept a proton)

• hydrophilic

Sulfhydryl (-SH)

sulfur bound to hydrogen

• polar

• hydrophilic

Phosphate (-PO4H2)

oxygen bonded to a phosphorus bonded to 1 oxygen, 2 OH’s; 1 double bond present

• acidic (lose proton)

• hydrophilic

Methyl (-CH3)

carbon bounded to 3 hydrogen, all single bond

• nonpolar

• hydrophobic

Macromolecules

large molecules

polymers

produced by linking monomers

monomers

identical or very similar building blocks

Put macromolecules, polymers, and monomers in order from smallest to largest

• monomers

• polymers

• macromolecules

dehydration reaction

synthesizing a polymer resulting in removing a water molecule (hydroxyl reaction with a hydrogen)

• enzyme: dehydrogenase

Hydrolysis

breaking down polymers by adding a water molecule

• enzyme: hydrolases

CC dehydration reaction and hydrolysis

dehydration reaction remove water to make bigger molecules while hydrolysis breaks things down using water

Monosaccharides

single sugars

• carbons

• carbonyl

Disaccharides

two monosaccharides formed through dehydration reaction

• covalent bond called GLYCOSIDIC LINKAGE

Polysaccharides

polymers of monomers linked together through GLYCOSIDIC LINKAGE

functions:

• storage

• structure

Carbs

made of”

• carbon

• hydrogen

• oxygen

monomers = sugars

Can lipids be polymers?

no, lipids can’t be polymers

can lipids have a theoretically infinite chain?

no, they do not have a theoretically infinite chain

lipids are..

hydrophobic

nonpolar solvents can dissolve

lipids

Fatty acids are made of…

long hydrocarbon with carboxyl group thru ester linkage

glycerol:

3 carbon alcohols, 3 -OH group (hydroxyl)

Fat Synthesis

dehydration reaction

Saturated Fatty Acids

solid at room temp (single bond)

unsaturated fatty acids

double bond fewer H than max

Phospholipids:

glycerol + 2 fatty acids + phosphate group

• amphipathic

the functions of Lipids are

• storage

• structure

• signaling

Proteins

monomers: amino acids

HYPROPHILIC

structure:

• central carbon

• hydrogen atoms

• amino group

• carboxyl group

• R group - side chain

What type of bond connects amino acids?

peptide bonds

Are polypeptides protein?

NO, although they are made of amino acids, they are not yet proteins because they aren’t specific or in the correct space

Protein Structure:

Primary:

• sequence polypeptide

Secondary:

• short distance attractions between hydrogen and develop into alpha helice

Tertiary:

• long distance side chains allow various leves of connection (ionic+ covalent)

Quaternary:

• more than one polypeptide chain

What is the impact of Denature

the loss of structure results in a loss of function

what causes a protein to denature?

• PH changes

• salt concentration

• high temperature

What is a restriction of renature?

renature is time sensitive

What is the function of a protein?

structure, signaling, enzymes, defense, and transport

Nucleic acids

DNA & RNA

SEQ the process of abiogenesis

1. Abiotic synthesis of monomers

2. Formation of organic macromolecules

3. Formation of protocells

4. Appearance of self-replication

what are the requirements for Abiogenesis

• low O2

• energy source

• chemical components (ex. CO2, H2O, CO, N2)

• Lots of time

CC Protocells and regular cells

Protocells: aggregates of ABIOTIC produced organic macromolecules

they both: divide, lipid bilayer, kinda homeostasis, electrical potential, osmatic swelling (electrical potential across surface)

they don’t have: no organelles, no metabolism, no DNA

Vesicles

fluid filled compartments

abiotic synthesis

molecules form spontaneously

Ribozyme

RNA with enzymatic properties, it can make copies of itself

Prokaryotes

no nucleus

Eukaryotes

has nucleus

endosymbiosis

little thing eats small thing (failed phagocytosis)

evidence of endosymbiosis

double membrane is evidence of endosymbiosis and mitochondria and chloroplasts have their own DNA (they do binary fission)

cell

smallest unit that carries out all activities associates with life

cc Prokaryotes v. Eukaryotes

• prokayotic: circular DNA, no nucleus, dna in nucleoid

• shared: DNA, ribosomes, DNA, cell wall,

• eukaryotes: membrane bound organeles, divide by mitosis, golgi

nucleus

stores DNA

nuclear envelope

surrounds nucleus

nucleolus

makes ribosomes

ribosomes

are not organelles because they are not membrane bound

• responsible for protein synthesis

mitochondria

aerobic respiration, generate ATP