Unit 1 Flashcards
Organic
Made of Hydrogen and Carbon (98%) are made of 6 elements
Carbon, Hydrogen, Oxygen, Phosphorous, Sulphur, Nitrogen,
Isotopes
different forms of atoms
radioisotopes
Nucleus of atom is unstable and give off matter which is detectable by radioactivity
INTRA
inside molecule bonds
give and take electrons
full charges involved
metals + non-metal
e.g. NaCl
INTER
between molecules
- Share E-
-partial/no charges
only contain non-metals
e.g. H2O
Polarity
Electronegativity- how much atom wants to become stable
Biological systems- determines interactions + neutrons
unequal sharing of electrons results in a polar covalent bond (slight charge)
Polar
Attracted to water, hydrophillic
nonpolar
molecules are hydrophobic
4 chemical reactions
Neutralization
Oxidation Reduction
Condensation reactions
Hydrolysis
Neutralization
acids dissolve in water ( H ion increase)
base- hydroxide ion inc
redox
one gains electrons (reduction)
loses electrons (oxidation)
condensation (dehydration synthesis)
water is used to build larger molecules
Water is a ……… molecule
polar (uneven distribution of e-
7 characteristics of Water
- Cohesion
- Adhesion
- Low density
- High specific heat capacity
- High heat of vaporization
- Good solvent
- Water as reagent
Hydrogen Bonds
Weak attraction between positive hydrogen of one molecule and negative oxygen of another
one water molecule- 4 hydrogen bonds
not chemical bonds- no molecule formed
break + reform properties are because of water
Cohesion
clinging to itself, Xylem, transporting water and materials
Adhesion
Clinging to other substance
-pond skaters, xylem clinging molecules to walls of xylem
surface tension
How difficult it is to break the surface of a liquid
- Top molecules attempt to occupy the least amount of space making surface tension
Low Density
- Density of ice lower than water
forms layer on top and allows life during winter snow as insulator
High specific heat capacity
a lot of heat needed to raise temp.
environment stability
biochemical reactions in cells
high heat of vaporization
amount of heat needed to turn water–> gas
lots of energy to break Hydrogen bonds
-sweating, evaporation–> cooling
Good solvent
water very good for polar substances
SALT- water molecules surround salt negative parts of water (oxygen) is attracted to positive Na+ ion positive H on water is attached to negative chloride ion
Water as reagent
water participates in metabolic processes
acts as a metabolic source of H in photosynthesis
Proteins
Carboxyl and amino groups
carbs
only CHO (1:2:1)
every carbon has oxygen
Nucleic acids
RIngs, contqains N sometimes pentose sugar sometimes phosphate
Lipids
only CHO
-not every carbon has an attached oxygen
Proteins
Muscle structure, hormones, antibodies pathogens, hemoglobin for carrying oxygen, transport proteins for moving molecules across cell membranes, chemical messengers in the nervous system and many more NCC in a lot of them
Carbohydrates
Store energy and provide structure
sugar- ring structures
single rings easily go back to straight chains
easy to break down starch and glycogen
harder to break down cellulose, mainly in plants
Lipids
hydrophobic lots of hydrocarbons–> nonpolar covalent bonds fats, phospholipids, steroids
Disaccharides
Carbs- maltose, sucrose, lactose
Maltose
Glucose + gluose
Sucrose
Glucose + Fructose
Lactose
Glucose + galactose
Formation of disaccharides
OH on carbon-1 reacts with the OH on carbon-4 of the other monosaccharide
- forms a 1,4 glycosidic bond takes the form of bridging oxygen atoms that links 2 monosaccharides
-disaccharides and water molecule are produced
breaking a disaccharide
- bonds in the carbohydrates need to be broken to release single glucose monosaccharides to be used in respiration
-glycosidic bond is split in a process called hydrolysis - water added catalyzed by enzymes
polysaccharides
- formed when many molecules link up in long chains via condensation (dehydration reaction)
- ideal for storing energy
easily broken down into glucose via hydroysis
e.x. starch, glycogen, cellulose
starch
few branches, plant, spiral/branches, storage of alpha glucose
Glycogen
many branches of alpha glucose
human (vertbrates)
storage carbohydrate
in animals
Cellulose
No bracnhes- long structural support, chains of beta glucose plant cells
Starch
long chains of A- glucose
amylose
-1,4 glycosidic bridges
- spiral structure w/H bonds
- unbranched
- glucose can only be released from enzymes working at each
Amylopectin
1,4 and 1,6 glycosidic linkages
-branched structure
-branched structure
-can be broken down more rapidly
Glycogen
-store energy in animals/ fungi
- a gluclose units
- more 1,6 glycosidic bonds
-1,4 glycosidic bonds
- many side branches- can be broken down easily
- insoluble + compact (good for storages)
cellulose
structural components of plant cell walls
- made of long parallel chians of B- glucose 1,4 linkages
Chitin
Similiar in structure to cellulose but has N foudn in cell walls of fungi and exoskeletons
Lipids
Group of macronutrients- oils, fats, cholesterol
mostly made of C and H
lipids are non-polar (not soluble)
large complex molecules NON-REPEATING
Triglycerides
fats- solid at room temp
oils- liquid at room temp
function-long term energy storage
Fats and Oils
carbon + hydrogen + oxygen less oxygen than carbohydrates
made of glycerol and fatty acids
fatty acids
single fatty acid molecule contaisn an acid
carboxyl- COOH group attached to a hydrocarbon chain
most commonly even numbers
inc chain length- less solubility
Builiding a Triglyceride
condensation
-hydrogen atom on the glycerol bonds to the hydroxyl group on the fatty acid , water is released
Breaking a Triglyceride
-hydrolysis
-molecule of water is added to each ester bond to break it apart and the triglyceride is broken up into 1 glycerol and 3 fatty acids
saturated
solid at room temp
present in mostly animal fats
e.g. meat, butter, dairy
unsaturated
liquids at room temp, present in plant fats, e.g. nuts, oils
Phospholipid tail polarity?
tails are hydrophobic- no charge, insoluble
Phospholipids function?
main structural component of cell membranes made up of glycerol, 2 fatty acids, and a phosphate group
Phosphate group (head of phospholipid) polarity?
Hydrophilic, water loving, polar
Types of Lipids 2 other
Waxes, steroids
waxes
long chain fatty acid
others act as barrier or waterproof coating
steroids
signaling molecules
- certain 4 fused hydrocarbon rings and several different functional groups
ex. cholesterol, testosterone, progesterone, estrogen
Function of Cell membrane
- Border of cell
-controls what comes in and goes out
-takes in and excretes substances
-food in waste out
-communcation!
3 Main component of cell membrane
-Lipids
-Proteins
-Carbohydrates
Lipids (main component purpose?)
main component
Protein (main component purpose)
transport
Carbhydrates
(communication)
Why Do Cell membranes have a particular structure
- outside of cell has water, inside has water
-hydrophilic heads are in contact with water only
-hydrophobic lipid tails are never in contact with water
-they block substances from passing through
What is the name for the cell membrane model?
Fluid mosaic
Fluid mosaic model
-fluid portion is the phospholipid bilayer 2 layers of phospholipids
- bilayer is flexible (shape can change)
-phospholipids are not bonded together
lipids and some proteins may dirt laterally within the membrane
Membrane fluidity
Lipid composiiton
-saturated or unsaturated
tight pack v loose
-temperature
too low= solid
more unsat.= lower gelling temp
Sterols -cholesterol
Sterols
cholesterol
-allows cells to function in a wide range of temperatures stays solid at high temps and liquid at low temps
Proteins embedded in membrane form a ….
mosaic
Cholestrol
found along side the phospholipids in the membrane
-membrane stabolizer
-minimizes the effect of temperature
- low temps keeps phospholipids from packing together
Proteins (cell membrane)
transport
enzymes
-signaling- bind chemicals to trigger changes on inner surface
-attachment points for cytoskeleton
-recognize microbes to trigger immune response
Integral membrane proteins
Embedded
-one region is anchored to hydrophobic core of membrane
-segments of polar amino acids at each end and nonpolar in middle
-part of the way or all the way through
transmembrane proteins-span the entire membrane
Peripheral membrane proteins
found on outer or inner surface of membrane
-do not touch the hydrophobic core
-mostly on the cytosol side
- part of cytoskeleton
Carbohydrates
outer surface (extracelluar)
Glycoprotein
bound to a protein
glycolipid- bound to a lipid
cellular markers - cell to cell recognition
-immune response
Membrane Permeability
Membranes can be semi or selectively permeable
-control what goes in and out
-some things can pass in/out easily
-some things require specific structures
some require energy
Types of transport
Passive and Active
Passive:
movement without energy use
active
movement with energy use
Transport across the membrane (all subtypes)
- Passive transport
- Facilitated diffusion
- active transport
- edocytosis
- exocytosis
Which is a faster method of concentration gradient simple or facilitate?
Facilitated diffusion the maximum rate is reached quickly but limited to number of transport proteins
Passive: Diffusion
Movement of molecule from high concentration to low concentration until they are at dynamic equilibrium
2 types
- simple diffusion
-facilitated
Facilitated Diffusion
Diffusion is ‘helped’ by membrane proteins
- Transport proteins protect charged/polar molecules from hydrophobic core by providing a route through the membrane
Channel Proteins
- Transmembrane proteins
- Makes a hydrophilic tunnel for water and ions (Na+ K+, Cl-) to pass
-very selective - some are voltage gated (open and closed based on electrical charges across the membrane)
Aquaporins
Channel proteins specifically for water
Carrier Proteins
- change shape to move a specific molecule across the membrane
- slower than channel proteins
Osmosis
- The passive diffusion of water across a membrane
-movement of water from a high concentration (Low solute) to low concentration (high solute)
Tonicity
The ability of an extracellular solution to make water move in and out of a cell
Isotonic
concentration is equal inside and outside
Hypertonic
Concentration of a solute molecules outside the cell is higher than the concentration in the cytoplasm
Hypotonic
concentration of a solute molecules inside the cell is higher than the concentration outside the cell
Active Transport
Cell expends energy (ATP)
- moves materials against the concentration gradient
Sodium Potassium Pump
3 sodium out: 2 potassium in Protein goes back and forth between 2 shapes
- inward facing -high affinity for Na+
-Outward facing = high affinity for K+
-plays major role in establishing membrane voltage (which then powers other pumps)
Secondary Active Transport
Uses energy stored in electrochemical gradients set up by primary pumps to move substances against their gradient
- The transport of 1 substance is used to transport a 2nd simultaneously
2 Types of secondary active transport
symport and Antiport
Symport
molecules moving in the same direction
Antiport
molecules move in opposite directions
What kind of transport for small and nonpolar
simple diffusion
Larger polar molecules, ions
Facilitated diffusion
Molecules moving against their gradient coupled to the hydrolysis of ATP
Primary Active Transport
Molecule going with a molecule moving against a gradient
Secondary active transport
Globular proteins
polymers of amino acids
-these amino acids join together in a long chain that folds to make a unique 3D structure
Enzyme facts
Proteins that help chemical reactions take place
-speed up reactions (catalysts)
- reactions can occur at lower temperatures
Enzymes
Facilitate chemical reactions
- increase rate of reaction (not consumed)
-reduces activation energy
- doesnt change the energy released or required
- required for most reactions
- highly speicifc (thousands in cells)
- Control reactions of life
Substrate
Reactant which binds to the enzyme
Product
end result of a reaction
Active Site
Enzymes catalytic site (substrate fits here)
Enzyme substrate complex
The complex formed when the substrate and enzyme interact
Hydrogen Peroxide
Hydrogen peroxide (H2O2) is a toxic chemical but is actually a byproduct of metabolism
Properties of enzymes
- reaction specific
each enzyme works with a particular substrate
-H bonds and ionic bonds - Not consumed in the reaction
they are unaffected
single enzyme can catalyse thousands of substrates/sec
-Affected by cellular conditions
-any condition that affect protein structure
-temperature, pH, salinity
Naming Conventions
Enzymes are named for the reaction they catalyze
sucrase
breaks down sucrose
Proteases
break down proteins
Lipases
break down lipids
DNA polymerase
builds DNA
Pepsin
breaks down proteins (polypeptides)
Types of enzymes
Intracellular
Extracellular
Intracellular
Work in animal and plant cells
e.g DNA polymerase, ligase
Extracellular
Secreted by cells and work outside the membrane
e.g. lysozyme
Enzyme mechanism models
Lock and Key
Induced Fit
Lock and Key
Not widely accepted Enzyme has a complementary shape to the substrate
induced fit
More accepted model Enzyme moulds itself around the substrate upon binding
Flagella
Used to help the cell swim around the cell
Centrioles
Paired structures involved in animal cell divison
Lysosome
Contain digestive enzymes that help break down the food
Cillia
Fine hairs on the cells surface
Nucleus
The control centre of the cell
Organelles
Small units that have specialized functions in the cell
Nucleolus
Located within the nucleus manufactures ribosome parts
Golgi apparatus
Package proteins and secrete it outside the cell
Endoplasmis reticulum
It acts as a passageway for materials moving to and from different parts of the cell and connects the nuclear membrane to the cell membrane
Vacuole
Provide storage areas for food, minerals, and water
Microfilaments
a fibre that consists primarily of subunits of the protein actin. that provide pathways for organelle movement
Microtubules
Pipe-like structures that provide shape and support for cell movement, produced by the centrioles
Ribosome
Manufacture proteins in the cell
Cytoplasm
Fluid substance in a cell that supports the organelles
Cell membrane
Controls the movement of materials in and out of the cell, and allows the exchange of food and gases
Mitochondria
Powerhouse of the cell
Bulk transport
Large particles (or big quantities of small partciles) are transported across the membrane
- involved enclosing substances in their own small globes of membrane
Exocytosis
Export- substances out of cell
- vesicles use with the plasma membrane releasing contents to exterior of cell
- hormones from endocrine glands or digestive juice from pancreas
Endocytosis
Move particles in by enclosing them in a vesicle made out of plasma membrane
- substances are trapped in a pit/depression which pinches off, trapping the particles
e.g. phagocytosis or pinocytosis
eating vs drinking large substances vs fluids/solute
Phagocytosis
cells engulf bacteria, viruses, parts of dead cells, etc.
e.g. macrophages (white blood cells)
Receptor- mediated endocytosis
Form of endocytosis in which receptor proteins on the cell surface are used to capture a specific target molecule
receptors- proteins clustered in coated pits
eg LDL cholesterol
Exocytosis
bringing out
