Unit 1: Cells
Eukaryotic
Both
Mitochondria- Double-membrane organelles with an inner membrane folded into structures called cristae, and a fluid-filled space called the matrix.
The site of aerobic respiration, producing ATP (energy) through the oxidation of glucose and other substrates. Also involved in metabolic processes and apoptosis
Nucleus- A membrane-bound organelle containing chromatin (DNA and proteins) and a nucleolus, surrounded by a double membrane (nuclear envelope) with pores.
Function: Acts as the control center of the cell, housing genetic material (DNA) and regulating gene expression, growth, metabolism, and cell division
Animal
Lysosomes- Membrane-bound vesicles containing hydrolytic enzymes. Digests and recycles cellular waste, worn-out organelles, and foreign substances
Centrosomes- Centrosomes consists of two centrioles (in animal cells), which are cylindrical structures composed of microtubules. Involved in organizing microtubules during cell division (mitosis) and forming the mitotic spindle.
Plant
Chloroplasts- Site of photosynthesis, where light energy is converted into chemical energy. Double membrane-bound organelle with internal stacks of membranes called thylakoids (containing chlorophyll), surrounded by fluid called stroma
Cell Wall- Provides structural support, protection, and regulates cell growth. Rigid outer layer made of cellulose
Large Central Vacuole- Stores water, nutrients, and waste products; provides turgor pressure for maintaining cell structure. Large membrane-bound sac (larger in plant cells)
Prokaryotic
Bacteria
Archaea
Unit 1: Chemical Bonds
Intermolecular
(Ex. Bond between H20 + H20)
Hydrogen Bonding
Ion-Dipole
London Dispersion Forces (Van Der Waals)
Dipole-Dipole Interactions
Intramolecular
(Bonds in-between atoms/element)
(Ex. O-H in H2O)
Ionic
(The attraction of opposite charges, cations and anions)
Example: Na+ and Cl- make NaCl (table salt)
- The 1 electron in Na+ valence shell if taken by the Cl- to fill its octet.
Occurs when electrons are taken rather than shared between atoms, within a molecule.
Covalent
(Sharing of electrons)
Non-polar
Example: C-H(Hydrocarbon, 0.4 EN difference), CO2(linear molecular shape).
Occurs when electrons are shared equally between atoms, within a molecule.
Polar
Example: C-O( 1.0 EN difference), O-H(1.4 EN difference), N-H (0.9 EN difference).
Occurs when there is an unequal sharing of electrons between atoms, within a molecule.
They are still willing to share though!
Bio-molecules
Proteins
Quaternary level:
Tertiary level:
Secondary level:
Primary Level:
Carbohydrates
Glycogen:
Used for storage and
branches extensively
Cellulose:
Found in plants exclusively
and provides structure, does not branch at all
Beta glucose:
The OH on the first Carbon group
is above the center of the molecule
Biomolecules: Nucleic Acids + Lipids
Nucleic Acids
Deoxyribonucleic Acid (DNA)
Double stranded helix where each polynucleotide strand has monomers with deoxyribose sugar and nitrogenous base
Nitrogenous bases include:
-Adenine (A)
-Guanine (G)
-Cytosine (C)
-Thymine (T)
Purines:
-a six-membered ring fused to a five-membered ring
Members include:
-Adenine
-Guanine
Genetic material inherited from parents. Each chromosome from the long DNA molecule contains several hundreds of genes
DNA helps provide instructions for the cell to develop and reproduce by providing the genetic material for all of the proteins that the cell may need.
Ribonucleic Acid (RNA)
Single stranded polynucleotide where each nucleotide monomer with a ribose sugar and nitrogenous base
Nitrogenous bases include:
-Adenine (A)
-Guanine (G)
-Cytosine (C)
-Uracil (U)
Pyrimidines:
-one six-membered ring of carbon and nitrogen atom
Members include:
-Cytosine
-Thymine
-Uracil
Lipids
Large biomolecules that include fats, phospholipids, and steroids
Steroid
contains carbon skeleton with four fused rings containing a variety of chemical groups attached
Fat
triglyceride: 3 fatty acids that are linked to a glycerol molecule, fatty acids have long carbon skeletons with a functional group and non-polar C-H bonds in the hydrocarbon chains
Phospholipid
made of glycerol with two fatty acids and a phosphate group; they can form bilayers and function as a membrane
Enzymes
Ex. sucrose
Inhibitors
Competitive
mimics and competes with the substrate to try and bind with the active site. Overall prevents the substrate from binding.
Non-competitive
binds to the enzyme away from the active site , altering the shape of the enzyme so that even though the substrate can still bind, the active site functions much less effectively, if at all.
Starch:
Used for storage and
consists of Amylopectin, which creates branches, as well as Amylose which does not branch out
1,4 Glycosidic Linkage:
A linkage between the first
Carbon group of a monosaccharide
and the fourth Carbon group of another monosaccharide
Allosteric regulation
active to inactive depending on the reactions needs
enzymes and proteins with quaternary structures
Cooperativity
substrates to control the functionality of an enzymes. The binding of one substrate can active other enzymes subunits into their active forms
Feedback Inhibition
prevents a cell from wasting chemical resources by synthesizing more product than is needed.
the product acts as a noncompetitive inhibitor and inhibits the first enzyme of the pathway, causing the pathway to shut down and restrict the creation of more product.
Catabolic pathways
complex molecules into simpler ones
Ex. Cell respiration
C6H1206 + 6O2→6CO2 +6H20 + ENERGY
Anabolic Pathways
|
simpler molecules into complex molecules
Ex. Photosynthesis
6CO2 +6H20 + light → C6H1206 + 6O2
Need light energy to create sugar and oxygen
Energy Investment Phase:
2 ATP is used during the processes
Energy Payoff Phase:
4 ATP and 2 NADH made
Cell Communication
Enzymes
Enzymes are macromolecules that act as catalysts in chemical reactions in order to speed up reaction rate by lowering activation energy
Substrates
Reactant that enzyme binds to
Types of signaling
Local Signaling
Paracrine signaling
Synaptic signaling
Long distance signaling
Hormonal signaling
Critical Players:
Signaling Molecule/Ligand
The molecule that is released by the cell which is usually received by another cell
Receptor
The receptor is present in the target cells that is receiving the signal
Membrane Receptor
Intracellular receptor
Junctions
Gap Junctions
Junctions on the cell membranes that allow cells to connect to each other and have molecules and substances to go in and out of the cells, resulting in the direct diffusion of ions
Desmosomes
Junctions that provide adhesion between cells and allow for more larger ions and molecules to pass through, is an intermediate between gap and tight junctions
Tight Junctions
Junctions that try to prevent leakage and create a semi-permeable membrane which are more strict and selective on which ions get to pass
Plasmodesmata
The plant versions of Gap junctions, only present in plant cells
Laws of Thermodynamics
GIBBS FREE ENERGY(G): A thermodynamic property that is used to predict the spontaneity of a process based on the principles of the second law.
Free energy Change (ΔG ):
The difference between the free energy of the final state and the free energy of the initial state.
ΔG = G ( final state) - G ( initial state)
Spontaneous Reactions: For cell processes to occur without additional energy and its initial state is more than the final state (ΔG > 0 )
Exergonic Reaction: Since ΔG is negative (Reactants>Products) is does not need energy to occur.
Change = ΔG = ΔH - TΔS ΔH = Enthalpy (total potential of a system)
ΔS = Entropy(measure of temperature)
Equilibrium: ΔG=0, no net change
Non-Spontaneous: When cell processes need energy to start a process in the cell it is non-spontaneous and ( ΔG < 0)
Endergonic Reaction: Since ΔG is positive (Products>Reactants), it needs to absorb energy to continue the cellular process and bond breakage.
Cellular Respiration
Pyruvate Oxidation
Step 1:
Pyruvate is taken from the glycolysis process and moved to the mitochondria and oxidized, giving electrons to to NAD+ to make NADH (requires O2)
Acetyl Coenzyme A:
A byproduct of pyruvate losing an electron, but necessary for the citric acid cycle
Gylcolysis
Step 1:
A phosphorus from ATP is added to glucose with the help of Hexokinase
to form glucose6P
Step 2:
Glucose6P is turned into fructose6P with the help of phosphogluco-isomerase
Step 3:
Fructose6P is converted into fructose1,6 bisphosphate by using a phosphate from an ATP and the help of phosphofructokinase
Steps 4/5:
The enzyme aldose splits fructose1,6 bisphosphate into glyceraldehyde 3-phosphate (G3P) and DHAP and the molecules are differentiated
Step 6:
G3P is oxidized and an electron is removed from the G3P and given to NAD+ to form NADH, while G3P becomes a byproduct that is given a phosphate group
Step 7:
The byproduct from the previous reaction then gives ADP one of its 2 phosphate groups to form ATP and form another byproduct
Steps 8/9:
An enzyme rearranges the byproduct to make another byproduct which is then processed by enolase to form phosphoenol-pyruvate(PEP)
Step 10:
The phosphate group from PEP is transferred to ADP to make ATP and PEP is turned into pyruvate
Citric Acid Cycle
Step 1:
Acetyl coenzyme A enters the citric acid cycle and interacts with oxaloacetate to form citrate
Step 3:
Isocitrate is oxidized and NAD+ is turned into NADH, while isocitrate is processed into ketoglutarate
Energy Production:
3 NADH, 1 ATP, and 1 FADH2
Oxidative Phosphorylation
Unit 2: Cell Membranes
Cell Membrane Structure
Hydrophilic- water loving heads
Hydrophobic- water repelling tails
Channel Protein- facilitate the transport of substances across a cell membrane through a process called facilitated diffusion. This process moves molecules from high to low concentration without using energy
Carrier Proteins- transmembrane proteins that move molecules and ions across cell membranes. They are responsible for transporting small molecules from areas of low concentration to areas of high concentration, against a biochemical gradient
Receptor Proteins- a special class of proteins that function by binding a specific ligand molecule. When a ligand binds to its receptor, the receptor can change conformation, transmitting a signal into the cell.
Cholesterol- Provides membrane fluidity and stability
Carbohydrates -help with cell recognition and protection, which are important for selective permeability of the cell membrane
Functions of Selective Permeability
maintains internal environment
Receptor proteins bind signaling molecules
Barrier against harmful substances
Types of Transport
ATP; the energy coupler or currency of the cell.
3 phosphates with negative charges
hydrolysis occurs on inorganic phophate
Heat is released so high free energy is left
ATP acts as a Endergonic and exergonic coupler
First Law:
(Principle of conservation of energy)
Energy can be transformed and transferred but cannot be created or destroyed.
Example: Consuming food, there is stored energy in the bonds we are eating! potential->kinetic
Second Law: (Principle of entropy increase)
Example: Food allows animals to run and release heat which increases disorder/entropy. There would be more order than normal but there is still order. For Biology, we need order.
Exergonic reactions as they are th only reaction that allows cells to do work. REACTIONS NEED TO END UP NEGATIVE
Makes ATP as energy is needed to make ADP into ATP with the addition of a phosphate group
Every energy transfer or transformation increases the entropy or disorder of the universe!
Enzyme active site ( a spacious pocket for bindng)
Enzyme-Substrate complex that weakens the substrates bonds for reactions to occur easier
ADD PHOTOSYNTHESIS TO THE SECOND MAP
Gene Expression
Transcription
The creation of mRNA from DNA genes to further go onto be a protein in translation
Prokaryotic Transciption
The Cytoplasm of a Prokaryotic cell
Subtopic
Eukaryotic Transcription
The Nucleus of a Eukaryotic cell
Subtopic
Concept Map 3
Unit 3: DNA Replication
Initiation Origin of replication-Specific DNA sequence where replication begins.
-Helicase unwinds the DNA.
-Primase lays down RNA primers
Elongation Leading strand: Synthesized continuously in the 5′ to 3′ direction.
Lagging strand: Synthesized discontinuously as Okazaki fragments
Termination Replication ends when replication forks meet or reach termination sequences.
Ligase joins Okazaki fragments
Helicase- Unwinds the double helix by breaking hydrogen bonds between bases.
Topoisomerase- Relieves supercoiling ahead of the replication fork.
Single-Strand Binding Proteins (SSBs)- Prevent reannealing of separated strands.
Primase- Synthesizes RNA primers to initiate DNA synthesis.
DNA Polymerase
DNA Polymerase III: Adds nucleotides in the 5′ to 3′ direction.
DNA Polymerase I: Replaces RNA primers with DNA.
Ligase- Seals nicks in the sugar-phosphate backbone, especially on the lagging strand.
Semi-conservative
The two strands of the parental
molecule separate, and each functions as a template for synthesis of a new, complementary strand.
Conservative
The two parental strands reassociate after acting as
templates for new strands, thus
restoring the parental double helix.
Dispersive
Each strand of both daughter molecules contains a mixture of
old and newly synthesized DNA
Replication Fork: Y-shaped structure where replication occurs.
Okazaki Fragments: Short DNA fragments on the lagging strand
Template Strand: The parental strand used to synthesize a complementary strand.
Telomeres: Protective ends of linear chromosomes.