General Biology I Exam I

nervous system

made of neurons & supporting cells

neuronal plasticity

concept that the nervous system can be modified after birth based on activity

synapses

specialized junction that allows a neuron to pass an electrical or chemical signal to another cell

synaptic transmission

biological process by which a neuron communicates with a target cell

memory

anatomical/physiological event at synapses

learning

using knowledge/experience to decrease the likelihood of a negative outcome

MEMORY ≠ LEARNING

MEMORY ≠ LEARNING

long-term potentiation (LTP)

lasting increase in strength of synaptic transmission

What is LTP facilitated by?

Facilitated by organization, chunking, and activity

Chunking

binding individual pieces of info into larger, meaningful groups

What are examples of active learning?

Workshop! —> Organizing content, making outlines, flowcharts/tables

How long is Short Term memory (STM)?

Seconds to minutes

What is the capacity of STM?

7 items

If not used, what happens to STM?

Forgotten/released

Where is information retrieved?

STM

Encoding

transforming perceived sensory input into something the brain can store and later retrieve

Retrieval

process of accessing and bringing previously encoded and stored information from LTM into STM

What is the duration and capacity of LTM?

Infinite

CANNOT DIRECTLY USE INFO FROM LTM!!

CANNOT DIRECTLY USE INFO FROM LTM!!

Evolution

all organisms are modified descendants of common ancestors

Emergent properties

arise from arrangement and interaction of parts —> absent from individual components

Hypothesis

testable proposed explanation

Prediction

expected outcome when testing it

Theory

broad explanatory framework

Law

statement of what occurs under specific conditions

SEQ of Scientific Process

observation, question, hypothesis, prediction, test (experiment), analyze data, conclusion, revise or repeat.

4 most common elements in living things?

CHON

When electrons are in a higher shell, do they have more or less potential energy?

Higher shell = further from nucleus = more PE

Valence electrons

Electrons in outer shell

Electronegativity

atom's pull on electrons

Relationship between chemical bonds and energy?

Chemical bonds represent potential energy

Nonpolar covalent bonds

Equal sharing of e-, equal or very similar electronegativity

Polar covalent bonds

Unequal sharing, partial + and partial - charges

Ionic bonds

Attraction between ions after e- gained/lost, highly unequal electronegativity

Hydrogen bonds

partial charges when H “bonds” to a strongly electronegative atom (O or N for us)

Van der Waals

Short-lived, weak, from e- position and motion

Which bond is the strongest under biological conditions?

Covalent bonds

Hydrogen bonds are what type of interaction?

Van der Waals interactions

London dispersion forces

occur between all atoms and molecules due to temporary, fluctuating shifts in electron clouds

What is the weakest type of intermolecular force?

London Dispersion forces

Cohesion

Water-water attraction

Adhesion

Water-other substance attraction

Temperature moderation

High specific heat (due to cohesion)

Ice floats

Crystals have greater distance between molecules than liquid

"Universal" solvent

Polar substances dissolve: hydrophilic = polar, dissolves; hydrophobic = nonpolar, doesn't

Hydrocarbons

molecules made of only C and H

Properties of hydrocarbons

Hydrophobic, nonpolar

Hydroxyl group properties

Polar, hydrophilic

Carbonyl group properties

Polar (less than OH), hydrophilic

Carboxyl group properties

Acidic, Polar, hydrophillic

Amino group properties

Basic, Polar, hydrophilic

Phosphate group properties

Acidic, Polar, Hydrophillic

Methyl group properties

Nonpolar, hydrophillic

Dehydration synthesis

builds larger molecules (monomers joined, water removed)

Hydrolysis

breaks larger molecules into smaller ones (water added)

Polymers

chains of monomers

LIPIDS ARE NOT POLYMERS

LIPIDS ARE NOT POLYMERS

Amphipathic

Has both hydrophobic and hydrophilic regions

Carbohydrates monomers

Monosaccharides

Proteins monomers

Amino acids

Nucleic Acids monomers

Nucleotides

Carbohydrates linkages

Glycosidic linkages

Lipid linkages

Ester bonds

Proteins linkages

peptide bonds

What are fats made up of?

Glycerol & fatty acids

What are phospholipids made up of?

glycerol + fatty acids + phosphate

Structure of steroids

Ring structure

Function of Carbohydrates

Storage and structure

Function of Lipids

Energy storage, membranes, signaling

Function of proteins

Structure, signaling, enzymes, defense, transport

Examples of carbohydrates

Starch, chitlin

Examples of lipids

Steroid hormones

Examples of protein

Collagen, Insulin

PHOSPHOLIPIDS ARE AMPHIPATHIC

PHOSPHOLIPIDS ARE AMPHIPATHIC

Amino acid parts?

central C, H, carboxyl group, amino group, R group (side chain)

Denaturation

when a biomolecule loses structure and function

Protein Structure Primary level

when amino acids come together to form peptide bonds

Protein Structure Secondary level

Hydrogen bonds form between carboxyl group & amino acids within a polypeptide strand —> Can form alpha-helix or beta-pleated sheet

Alpha helix

spiral or coil shape

Beta-pleated sheet

Folded, accordion-like zig-zag sheets

Protein Structure Tertiary level

when multiple bonds form between different r-groups

Protein Structure Quaternary level

when multiple polypeptide chains come together and coil up

Causes of Protein Unfolding

Denaturation can happen from pH, temperature, salt concentration

Why are lipids not polymers?

Because they are not built from long chains of repeating monomer subunit

Abiogenesis

scientific theory that life on Earth originated naturally from nonliving organic and inorganic matter

SEQ abiogenesis

Abiotic synthesis, formation of organic macromolecules, formation of protocells, self-replication

Abiotic synthesis

Simple inorganic molecules combined using external energy sources to form basic organic monomers

Formation of organic macromolecules

can form on clay or rock surfaces & helped by metal ions

Formation of protocells

self-organized, lipid- or polymer-based compartments that predate living cells and provided the isolated environment needed for early biochem rxns

Vesicle

fluid-filled compartment surrounded by membrane-like structures

4 requirements for abiotic synthesis

low oxygen, source of E, CHON, lots of time

Self-Replication

RNA probably came first —> RNA served as both heredity and enzymes

RNA-peptide world hypothesis

1st replicating systems used RNA to store & copy genetic info —> DNA came later

Prebiotic Soup Hypothesis

life formed near Earth’s surface through spontaneous formations of monomers

Iron-Sulfur World Hypothesis

life formed at cracks of ocean floor in hydrothermal vents

What were the first cells and what were some properties of them?

Prokaryotes with no nucleus —> Anaerobic, probably heterotrophic

Autotrophy

Use sunlight energy to make own organic molecules; the earliest released sulfur compounds

Cyanobacteria

Released O2, causing the oxygen revolution: oxygenated atmosphere, killed most life —> when aerobes became dominant

Eukaryotes

Nucleus and organelles; features via endosymbiosis

endosymbiosis

big cell engulfs a smaller cell —> smaller cell is incorporated as part of the bigger cell and becomes an organelle