Bio Exam 1 and 2

Conserved Structures

Structures that can be recognized in new forms. ex: flying squirrel

Cell Membrane

A structure that is fatty and separates the watery interior and exterior of a cell.

Cytoplasm

“Complex goo”. The cell is constantly regulating the mixture

DNA

Carries genetic information and makes RNA which tells cells how to make protein.

Ribosome

A structure that produces proteins

Structures in ALL cells

Cell Membrane, Cytoplasm, Ribosomes, and DNA

Prokaryote

Single cell organism

Eukaryotic Cells

Contain cell membrane, cytoplasm, chromosomes(DNA), ribsosomes, endomembrane system, membrane bound organelles, and cytoskeleton

Endomembrane System

A network of membranes and organelles inside eukaryotic cells that work together to modify, package, and transport lipids and proteins

Components of the Endomembrane System

Nuclear Envelope, Nucleoplasm, Rough and Smooth Reticulum, Lumen, Golgi Apparatus, and Vessicles

Membrane Bound Organelles

Chloroplasts and Mitochondria

Cytoskeleton

Array of supportive proteins, prevents gravity from crushing cells

Features of Chloroplasts and Mitochondria

Contain their own DNA and Ribosomes, self replication, and resemble prokaryotes

Phagocytosis

A cell can wrap its cell membrane around something and bring it in

Advantage of Endomembrane System

Compartmentalization

Endosymbiont Theory

Organelles evolved from “captured bacteria living symbiotically within early eukaryotic cells

Microtubles

Big hollow tubes that are unbendable (support in cytoskeleton)

Intermediate Filaments

Wont’t stretch or break, similar to cables holding up a bridge. ex: collagen

Extracellular Support

Cell Walls

Extracellular Matrix (ECM)

Anchors cells

Main elements in living organisms

Carbon, Hydrogen, Nitrogen, Oxygen (Phosphorus and Sulfur)

How do electrons occur

In shells

What are chemical bonds

A result from sharing unpaired electrons

How many unpaired electrons does Carbon have

4

How many unpaired electrons does Nitrgoen have

3

How many unpaired electrons does Oxygen have

2

Covalent Bonds

Equal electron sharing

Polar Covalent Bonds

unequal electron sharing

Ionic Bonds

electrostatic attraction of ions (full charges)

Electronegativity

only apparent when different elements combine

Electron Stripping (ions)

Extreme difference in electronegativity

Hydrogen Bonds

between polar covalent bonds

Hydrogen Bonding

between a positive hydrogen and negative oxygen

Emergent properties of water

surface tension, high specific heat capacity, evaporative cooling, less dense as a solid, universal solvent, and pH

Why does surface tension occur

Because hydrogen bonds are all the same length

Cohesion

water bonds to water

Adhesion

water bonds to other

Hydration Shell

a protective layer of water molecules that surrounds a dissolved ion, polar molecule, or biomolecule in an aqueous solution

Functional groups

alter the reactivity and chemical properties of organic molecules

pH

dissociation of water where certain amounts of H+ and OH- ions are formed

Hydroxl

OH

Hydroxl function

Adds polarity to molecules and is used for polymerization reactions

Carbonyl

C=O

Carbonyl functions

Used for oxidation-reduction reactions and effects shape of molecules

Carboxl

COOH

Carboxl function

Adds a negative charge (ion in water)

Amino

NH2

Amino functions

adds positive charge (ion in water)

Sulfhydryl

SH

Sulfhydryl functions

Make “di-sulfide bridges” and is important for protein structure

Phosphate

PO4

Phosphate functions

Adds energy to molecules for reactions

Methyl

CH3

Methyl functions

a temporary tag, makes molecules less polar

Dehydration Synthesis

A short polymer and unlinked monomer connect when dehydration removes a water molecule, forming a new bond

Hydrolysis

Adds a water molecule, breaking a bond

Lipids

Any hydrophobic biological molecule

Triglycerides

1 glycerol and 3 fatty acids

Fats

Triglycerides with saturated fatty acids - solid at room temperature

Oils

Triglycerides with unsaturated fatty acids - liquid at room temperature

Viscous

More unsaturated fatty acids

Fluidity

More unsaturated fatty acids

Phospholipid

1 glycerol, 2 fatty acids, 1 phosphocoline

Basis for cell membrane

Phospholipid bilayer

Cholesterol

Moderates fluidity by making fluid membrane more viscous and viscous membrane more fluid

Fluid Mosaic Model

Phospholipids are freely moving

Membrane fluidity

Diffusion of solutes

Polypeptides

Polymers of amino acid monomers

Primary Structure

Amino acid sequence

Secondary Structure

hydrogen bonds along backbone of same polypeptide - contains alpha helix and beta sheet

Tertiary Structure

Three-dimensional folding of sheets and helices of a single polypeptide - interactions between R groups

Quaternary Structure

more than one polypeptide chain together in a single structure

Integral Proteins

Transmembrane proteins (inside the cell membrane)

Peripheral Proteins

Proteins along the cell membrane

Diffusion

Net movement from a region of high concentration to a region of low concentration

Semi-permeable

Lets some things through but not others

Gradient

Difference in concentration

Passive Transport

We don’t need to spend any of our metabolic energy

Channel proteins

Mostly for ions, so a selective hole in the membrane is made

Carrier Proteins

At no point is there an open hole in the cell membrane

Uniport

An integral membrane protein that moves a single specific molecule or ion across a cell membrane at a time

Symport

A type of membrane transport protein that moves two different molecules or ions across a cell membrane in the same direction at the same time

Antiport

A membrane protein that moves two or more different molecules or ions in opposite directions across a cell membrane

Osmosis

Net movement of water (solvent) toward a higher solute concentration

Hypertonic

More total solute

Hypotonic

Less total solute

Isotonic

Same total solute

Active transport

transport that costs us energy

Protein pumps

Solutes move towards high concentration and requires metabolic energy

Coupled Transport

Multiple solutes transported by one protein

Bulk Transport

Instead of going through the membrane, use the membrane itself

Endocytosis

Bringing material into a cell using membrane to make vesicles

Exocytosis

Secretes material out of a cell by fusing vesicles with the membrane

Phagocytosis

“Cell eating”, non specific process

Pinocytosis

“cell drinking”, non specific process

Receptor Mediated Endocytosis

Very specific, receptors bind and accumulate a target molecule to bring in

Receptor Dimerization

two receptors come together when the ligand binds (protein shape changes)

Autophosphorylation

Transports phosphate group which adds energy

G-protein coupled receptor

Exchanges GDP for GTP and activates “downstream” enzyme

Signal Transduction

Reception, Signal Transduction Cascade, then Response