week 2. chemistry Flashcards
Chemical Elements
all forms of matter are
made up of these “building blocks”
Atoms
smallest units of matter that retain
the chemical characteristics and properties
of an element
Ions
an atom that has a positive or
negative charge due to an unequal
amount of protons and electrons
Molecules
when 2 or more atoms share
electrons (i.e. O2 or H2O)
Compound
a substance that contains
atoms from 2 or more elements (i.e. NaCl,
H2O)
Chemical bonding creates
molecules and compounds
Ionic bonds
Created by electrical attraction between
cations and anions
– Involves the transfer of electrons from one
atom to another to achieve stability
Covalent bonds
Sharing of electrons between atoms
Single covalent bond
One electron contributed by each atom
Double covalent bond
Two electrons contributed by each atom
Metabolism
Metabolism is the sum of all the cellular reactions
of the body at a given moment
– 2 types of reactions: Anabolism and Catabolism
– These reactions are controlled by enzymes
enzymes
protiens
Anabolism
larger molecules constructed from
smaller molecules. Requires energy (ATP).
These molecules will be used for cells to
function, repair and grow
Catabolism
larger molecules broken down into
smaller molecules. Creates energy (ATP). The
ATP generated from this reaction will be used for
the Anabolism reactions.
cellular respiration
breakdown of glucose
one glucose = _ ATP
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Cellular respiration steps 1-4
glycolysis, formation of Acetyol Co-A, Citric acid cycle, electron transport chain
In a chemical reaction, there is two types…
Reactants
• Participants at reaction start
• Usually on the left
– Products
• Generated at end of reaction
• Usually on the right
Activation energy
Amount of energy to start a reaction
Enzymes
Special proteins that lower the activation
energy for a reaction
– They allow the reaction to occur
Catalysts
Compounds that accelerate reactions
without changing themselves
– Reactions continue until equilibrium is
reached
– Enzymes perform as catalysts
Metabolites
All molecules that can be synthesized or
decomposed in our bodies
– Processed by enzymatic reactions
– Nutrients
Organic metabolites
Always contain carbon and hydrogen
Carbohydrates, lipids, proteins, ATP, DNA, RNA
inorganic metabolites
Generally do not contain carbon and hydrogen
» Examples:water
• many salts
• Acids
• bases
Water
chemical reactions occur in water, and water
molecules are also participants in some reactions,
intracellular fluid:
found inside the cells (2/3 of body fluid)
extracellular fluid
found outside of cells—examples are blood and
fluids found between cells (1/3 of body fluid)
extracellular fluid
found outside of cells—examples are blood and
fluids found between cells (1/3 of body fluid)
Electrolytes
control the fluid balance of the body and are
important in muscle contraction, energy generation, and
almost every major biochemical reaction in the body.
acid
proton donor
base
proton acceptor
pH
More H+ results in a LOWER pH (acid)
• Less H+ results in a HIGHER pH (alkaline/base)
• pH – a measure derived from the molarity of H+
– a pH of 7.0 is neutral pH
– a pH of less than 7 is acidic solution
– a pH of greater than 7 is basic solution
Carbohydrates
Carbs can be
quickly metabolized to generate energy (ATP) for the cell
Lipids
Found in all cell membranes (lipid bilayer)
– Used as a secondary source for ATP (lipid catabolism)—broken
down to generate ATP
– Form cholesterol and certain types of hormones
– Insulate organs
Proteins
a molecule made of smaller units called amino acids,100,000 kimds
ATP
body’s most important energy-transfer molecule
DNA (deoxyribonucleic acid)
Provides instructions for synthesizing all of
the body’s proteins
• transfers hereditary information from cell to
cell and generation to generation
RNA (ribonucleic acid)
carries out genetic instruction for synthesizing
proteins (brings instructions from DNA to the cell’s
ribosomes)
• assembles amino acids in the right order to
produce proteins
• RNA is the molecule responsible for synthesizing
the proteins
• Three types: mRNA, tRNA, rRNA
Cell theory
- Cells are building blocks of all plants and
animals - All new cells come from division of preexisting
cells - Cells are smallest unit that perform all vital
physiological functions
Cell division
Production of daughter cells from single cell
• Important in organism development and survival
• Cells divide because they wear out and need to be replaced, they are damaged, or more cells are needed for growth
two types of cell division
- Mitosis (2 daughter cells, each with 46 chromosomes)
- Meiosis (sex cells only, each with only 23 chromosomes
Cancer
when cells divide out of control—resulting in
cells that do not work and take over normal tissue
Cell membrane (plasma membrane)
Separates cell contents from extracellular fluid (fluid found outside of cells)
• Selectively allows substances in and out of cells (membrane is
selectively permeable). The movement is between the intracellular fluid
(found inside cells) and the extracellular fluid (found outside of cell)
Cytoplasm
Material between cell membrane and nuclear membrane
• Colloid containing many proteins
Phospholipid bilayer
Mostly comprised of phospholipid molecules in
two layers
• Hydrophilic heads at membrane surface
• Hydrophobic tails on the inside
• Isolates cytoplasm from extracellular fluid
organelles
Nonmembranous
• Not completely enclosed by membranes
• In direct contact with cytosol
Membranous
• Enclosed in a phospholipid membrane
• Isolated from cytosol
Microvilli
increase surface area for absorption
Cytoskeleton
Strength and support
• Intracellular movement of structures and materials
Ribosomes
site for the synthesis of proteins
Peroxisome
Catabolism (breakdown) of fats/other organic
compounds
• Neutralization of toxic compounds
Lysosome
Removal of damaged organelles or pathogens
Golgi apparatus
storage, alteration, and packaging
of synthesized products
Mitochondria
production of 95% of cellular ATP
(energy) via a process called CELLULAR
RESPIRATION
Endoplasmic reticulum (ER)
synthesis of secretory products, storage,
and transport
Smooth ER
No attached ribosomes
• Synthesizes lipids and phospholipids (used in
cell membrane) and steroids (such as
hormones). Stores calcium in muscle cells
rough er
Ribosomes are attached which give it a
“rough” appearance
• Produces and modifies proteins. Packages
them in vesicles for transport.
Nucleus
Control of metabolism
• Storage/processing of genetic information
• Control of protein synthesis
Cells
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DNA parings
A-T, C-G
Chromosome
tightly coiled DNA
RNA pairings
A-U. T-A. C-G. G-C
Simple diffusion
Movement across lipid
portion of membrane without a carrier
protein or any assistance (substances are
allowed to go through lipid bi-layer), HIGH TO LOW CONCENTRATION
Facilitated diffusion
Hydrophilic or large molecules transported
across cell membrane by carrier proteins
(these are embedded in the cell membrane) HIGH TO LOW CONCENTRAION
Active transport
Substances move from low to high
concentration so requires ATP
• Always facilitated: carrier/protein required
Osmosis
Net diffusion of water across a membrane—water moves
from high concentration of water to low concentration of
water (
Hypotonic
ECF (extracellular fluid) has a lower
concentration of salt/solutes than the cell
• Causes osmotic flow into cell
• Cell will burst
Hypertonic
ECF has a higher concentration of salt/solutes
than the cell
• Causes osmotic flow out of cell
• Example: crenation of RBCs
Why is cell membrane transport important?
Cells will die very quickly if they allow anything in and out
