Test 1

Overview of Biology

Overview of Biology

The study of living systems and their shared characteristics.

Shared Characteristics of Living Systems

Cellular structure, DNA, reproduction, growth/development, energy use, homeostasis, response to stimuli, and evolution.

order, sensitivity, adaptation

Basic Science

Pure science aimed at expanding knowledge without immediate practical application.

Applied Science

Technology-focused science that seeks to solve real-world problems.

Deductive Reasoning

A top-down approach where general premises lead to specific conclusions.

Inductive Reasoning

A bottom-up approach where specific premises lead to general conclusions.

Scientific Method

A systematic process involving observation, hypothesis formulation, testing, and analysis.

Levels of Biological Organization

Small → Large: Organelles, cells, tissues, organs, organ systems, organisms, populations, communities, ecosystems, biosphere.

3 Biological Domains

Archaea, Bacteria, Eukarya

Isotopes

one or more forms of an element that have different numbers of neutrons

Ions

Atoms or chemical groups with unequal numbers of protons and electrons.

Molecules

Structures formed by two or more atoms bonded together.

Compounds

Substances made of molecules containing at least two different elements.

Organic Compounds

Contain C-H bonds and are derived from living organisms.

Inorganic Compounds

Typically lack C-H bonds and may contain other elements.

Covalent Bonds

Strong bonds formed by shared electrons between atoms.

glycosidic linkage

Ionic Bonds

Bonds formed between oppositely charged ions.

Hydrogen Bonds

weak bond between slightly positively charged hydrogen atoms and slightly negatively charged atoms in other molecules

Properties of Water (Some of it)

Includes states (solid, liquid, gas), high heat capacity, and unique density characteristics.

Water has the highest heat capacity of any liquid

Polar: Hydrogen positivity (+1 times 2) and oxygen’s negativity (-2 times 1)

neutral: Universal solvent

Dissociates into H+ (pure acid) and OH- (pure base) (disassociation of ions generating pH)

Cohesion and adhesion

Cohesion

Attraction between water molecules due to hydrogen bonding.

Adhesion

water is attracted to other substances and sticks to any polar substance

Hydrophobic

Non-polar substances that do not interact with water (water-fearing).

non polar compounds (afraid of water) + the receptors can be inside the cell.

Macromolecules

Large molecules essential for life, including carbohydrates, lipids, proteins, and nucleic acids.

Cell Theory

All living things are composed of cells

The cell is the basic unit of life

New cells arise from existing cells.

Prokaryotic Cells

Simple, unicellular organisms without a nucleus or membrane-bound organelles.

Most prokaryotes have a cell wall for an extra layer of protection, and some have a flagella or pili for locomotion. Prokaryotes are 10 to 100 times smaller than eukaryotes.

found only in the domains Bacteria and Archaea

Eukaryotic Cells

Complex cells with a membrane-bound nucleus and organelles (endoplasmic reticulum, Golgi apparatus, chloroplasts, etc). Eukaryotes are 10 to 100 times larger than prokaryotes.

DNA tightly wrapped around histone proteins in chromosomes, cellulose in plant cell walls.

Plasma Membrane Transport

Includes simple diffusion, facilitated diffusion, active transport, and osmosis.

Simple Diffusion

Movement of small non-polar molecules from high to low concentration without energy.

Facilitated Diffusion

Does NOT use energy

Because Ions and polar molecules are impermeable to the membrane, a carrier/embedded protein lets them through

Embedded/transport/carrier protein: membrane protein that facilitates a substance's passage across a membrane by binding it

The inside of the carrier/embedded protein is polar, allowing polar molecules through

High → Low concentration

Active Transport

Requires energy (ATP)

Uses protein pump & ATP to cross

Protein pump: active transport mechanism that works against electrochemical gradients

Low -> High concentration

Osmosis

Water movement across the membrane

Water diffuses across cell membrane towards a lower water amount and higher solution concentration

Tonicity

Hypertonic solution, Hypotonic solution, and Isotonic solution

DNA

Stores the genetic information necessary for an organism to develop, function, and reproduce. “Blueprint for all living things.”

Reproduce

Organisms reproduce their own kind.

Grow/Develop

Organisms grow and develop as a result of genes providing specific instructions that will direct cellular growth and development.

occurs through genes/DNA providing for cellular growth

Homeostasis

The environment outside an organism can change, but the organism can adjust its internal environment/conditions.

process by which organisms maintain a relatively stable internal environment as the outside environment is changing

Respond

All organisms respond to environmental stimuli.

Evolve

Mutations allow the possibility for organisms to adapt to a changing environment, a process of gradual change in a population or species over time, life on Earth has evolved from three lineages / “domains”: bacteria, archaea, and eukarya.

Archaea

Archaeabacteria: unicellular, are often extremophiles, living in harsh environments that have no nuclei or organelles. lacks intracellular organelles (like Bacteria)

Bacteria

Eubacteria: Prokaryotic cells with microbes that lack membrane-enclosed nuclei and organelles. unicellular that lack nuclei and organelles. have a cell wall and RNA.

Eukarya

Protist, Fungus, plant, and animal: multicellular containing a distinct nucleus and membrane bound organelles that have DNA. examples include animals, plants, fungi

Kinetic energy

causes the bonds to break because of high heat in the system (water vapor), allowing the water molecules to escape as gas

Facts about ice

Ice floats because of the density compared to liquid water

Water molecules are pushed farther apart

When ice forms at the surface of a lake, it protects water organisms from freezing and dying

One way cells can survive freezing is if another liquid (ex: glycerol) replaces the water in the cell.

Acid

substance increasing hydrogen ions concentration in solutions (usually because one of the hydrogen atoms dissociate)

A chemical that gives off hydrogen ions in water and forms salts by combining with certain metals

Base

H- concentration within a solution or OH- in a molecule

a substance that can neutralize the acid by reacting with hydrogen ions.

Hydrogen bonding

Intermolecular force

dipole-dipole

Hydrogens in water will attract highly electronegative atoms (F, O, Cl)

Cause for the high density of water

Cause for the “stickiness of water”

Hydrophilic

when polar substances interact readily or dissolve in water (water loving) + in membranes the ligands are on the cell membrane.

Surface tension

Occurs because of cohesion. How a substance will withstand rupturing when placed under tension or stress. Allows for water molecules to ‘float’ to the top.

Solvent Properties

Solvent: Substance capable of dissolving other polar molecules and ionic compounds.

Sphere of Hydration: charges of molecules allowing for forming of hydrogen bonds with water (hydration shells).

Dissociation: Separation of atoms from molecules resulting in formation of ions.

Carbohydrates and it’s Building Block

The body's primary source of energy and the brain's preferred energy source.

include sugars and the polymers of sugars

macromolecules are polysaccharides, polymers composed of many sugar building blocks

Glucose & Monosaccharides (simple sugars)

Lipids and it’s Building Block

Help control what goes in and out of your cells.

Fatty acids, glycerol

Proteins and it’s Building Block

Structural support, biochemical catalysts, hormones, enzymes, building blocks, and initiators of cellular death.

Amino acids

Nucleic acids and it’s Building Block

Storage and expression of genomic information.

Nucleotides

Simple Diffusion

Does NOT use energy

Small non polar molecules or gasses that are permeable and pass through without help

High → Low concentration

Sodium Potassium Pump and it’s steps

Active transport of Na+ to extracellular fluid and K+ ions to the intracellular fluid across the cell membrane re-establishes an electrochemical gradient which has potential energy.

1. 3 sodium ions (Na+) bind to the pump

2. A phosphate from ATP is donated to the pump (Energy used)

3. The pump changes shape and releases Na+ outside of the cell

4. 2 potassium ions (K+) bind to the pump and a transferred into the cell

5. The phosphate group is released and the pump returns to its original shape

Osmolarity

Describes the solute in a water solution

Solutes that dissociate, increase osmolarity

A solution with more water molecules than solute particles has low osmolarity

Hypertonic solution

higher osmolarity (higher solute particle, lower water) in extracellular fluid vs cytoplasm

Hypotonic solution

lower osmolarity (lower solute partial, higher water) in extracellular fluid vs cytoplasm, plants cells prefer

Isotonic solution

relatively equal osmolarity in extracellular fluid and cytoplasm, animal cells prefer

Water Heat Vaporization

Turns at 100 degrees Celsius, 212 degrees Fahrenheit

The evaporation of sweat, which is 90 percent water, allows the organism to cool so that it can maintain homeostasis of body temperature

An animal will sweat, burn the water off their body via their skin, and transfer the heat/energy used to evaporate the water into the gaseous state of water, therefore cooling them

Human Genome Project

a research effort to sequence and locate the entire collection of genes in human cells. relied on basic research to then later find cures for genetic diseases.

order

how organisms respond to environment

reproduction

the process of producing offspring

adaptation

characteristic that improves an individual's ability to survive and reproduce in a particular environment.

energy processing

All organisms use a source of energy for their metabolic activities

evolution

Change in a kind of organism over time; process by which modern organisms have descended from ancient organisms.

phylogenetic tree

A branching diagram that represents a hypothesis about the evolutionary history of a group of organisms.

levels of matter

atoms, molecules, macromolecules, organelles

Structure of atom. Know where protons, neutrons, and electrons are located.

Composed of subatomic particles (protons, neutrons, electrons) with specific properties.

neutrons: no charge, located in nucleus

protons: positive charge, located in nucleus

electrons: negative charge, located on outside shells (2 in first orbital, 6 in others)

what determines the element's mass number

the number of protons + neutrons together

what determines the element's atomic number

the protons

Cation

A positively charged ion formed by loosing electrons

anions

a negatively charged ions that gains electrons

non polar covalent bond

a covalent bond in which the bonding electrons are shared equally by the bonded atoms, resulting in a balanced distribution of electrical charge

hydrogen bonds

weak bond where a hydrogen covalently bonds to an electronegative atom

liquid state of water

hydrogen bonds constantly form and break as the hydrogen atoms slide past each other

gaseous state of water

the kinetic energy makes heat rise as the water boils therefore the water molecules escape into the air

hydrocarbons

Compounds composed of only carbon and hydrogen

isomers

compounds that have the same molecular formula but different structures

ATP

(adenosine triphosphate) attached to three phosphates that is main energy source that cells use for most of their work

RNA

Mostly involved in protein synthesis and is the communicator of the cell.

Monosaccharides

glucose, fructose, galactose (simple sugars)

molecular formulas that are usually multiples of CH2O

– The location of the carbonyl group

– The number of carbons in the carbon skeleton

plant cell vs. animal cell organelles

plant cells: cell wall, chloroplasts, plasmodesmata, plastids

animal cells: centrioles, centrosomes, lysosomes

Rough ER vs Smooth ER function

- Rough ER: attached ribosomes, main site of protein synthesis

- Smooth ER: lacks attachment of ribosomes, main site for making lipids

Golgi apparatus function

modifies and packages proteins

Lysosomes function

Digestion and recycling (only in animal cells)

Plasmodesmata

An open channel in the cell wall of plants through which strands of cytosol connect from adjacent cells

allow connected plant cells to communicate and share resources

The three animal cell junctions

tight junctions, desmosomes, gap junctions

fluid mosaic model

Structural model of the plasma membrane that includes phospholipids, cholesterol, proteins, and carbohydrates giving the membrane a fluid character.

The fluid mosaic model describes the plasma membrane structure as a mosaic of components—including phospholipids, cholesterol, proteins, and carbohydrates—that gives the membrane a fluid character. Plasma membranes range from 5 to 10 nm in thickness.

Phospholipids

a lipid consisting of a glycerol bound to two fatty acids and a phosphate group.

Mircomoleules

large molecules composed of thousands of covalently bonded atoms

polymers, built from monomers

polymer

a long molecule consisting of many similar building blocks

– Carbohydrates

– Proteins

– Nucleic acids

monomers

small building-block molecules

dehydration reaction

occurs when two monomers bond together through the loss of a water molecule

An enzyme reaction linking monomers through the loss of hydrogen from one monomer and hydroxide from the other monomer to form a bond whose name varies by macromolecule group

C – glycosidic linkage

L – ester linkage

P – peptide bond

N – phosphodiester linkage

hydrolysis

Polymers are disassembled to monomers by by this process, a reaction that is essentially the reverse of the dehydration reaction

An enzyme reaction using water thereby adding hydrogen to one side and hydroxide to the other side of a bond within a polymer resulting in smaller molecules or monomers.

disaccharide

formed when a dehydration reaction joins two monosaccharides

Polysaccharides

polymers of sugars, have storage and structural roles

• The structure and function of a polysaccharide are

determined by its sugar monomers and the positions of

glycosidic linkages

Types of Polysaccharides

Starch, Glycogen, Cellulose, and Chitin

Starch

a storage polysaccharide of plants, consists entirely of glucose monomers

• Plants store surplus starch as granules within chloroplasts and other plastids

• The simplest form of starch is amylose

Glycogen

a storage polysaccharide in animals

Humans and other vertebrates store glycogen mainly in liver and muscle cells