Bio
Storage Proteins
Biological reserves of AA EG - Ovalbumin (eggs), Casein (milk), plant seeds
Nucleus
Membrane enclosed, contains most of the genetic material Nucleolus Nuclear Lamina
Cytoskeleton
Microtubules, microfilaments and intermediate filaments Aid in cell division, cell crawling and cytoplasm movement (eukaryotes)
Receptor Proteins (Membrane)
Binding site for hormones or other trigger molecules
Nucleoplasm
"cytoplasm" of the nucleus.
Water
1 - High heat capacity (requires a lot of energy to change the temperature) 2 - Cohesion/Surface tension (likes itself due to H-bonding) 3 - Adhesion - attraction of unlike substances (wet finger to turn page 4 - Unique solid density (less dense when frozen due to H-bonds crystal lattice structure) 5 - Strong solvent (excellent for separating charged ionic molecules)
Phospholipids
2 FA and a phosphate group on glycerol backbone AMPHIPATHIC - hydrophobic and hydrophilic properties
Triglycerides
3 fatty acid chains on a glycerol backbone Saturated - no double bonds, Bad for health Unsaturated - double bonds - better for health (stack less densely due to kinks)
Steroids
4 ring structure Used as hormones and structural component in membranes (cholesterol)
Mitochondria
ATP production Participate in FA Catabolism Have their own DNA Double layered membrane
Hydroxyl functional group
Alcohols Polar Hydrophilic
Cell Theory/Doctrine
All living things are composed of one or more cells Cells are the basic unit of structure, function, and organization in all organisms All cells come from pre-existing, living cells Cells carry hereditary information Energy flow (e.g. metabolism) occurs within cells All cells have the same basic chemical composition VIRUSES AREN'T LIVING
Enzyme regulation
Allosteric enzymes - Active site (binding substrate) - Allosteric site (binding allosteric effector - activator or inhibitor) Competitive and Noncompetitive Inhibition High Km = worse substrate binding Low Km = better substrate binding
Ion Channels
Allow passage of Ions Gated Ion channels in nerve and muscle cells - Voltage - difference in membrane potentials - Ligand (Chemical) - chemical binds and opens - Mechanical - respond to pressure, temp, vibration etc
Porins
Allow passage of certain ions + small polar molecules. These tend not to be specific, they're just large passages. Molecules that fit will diffuse through. Aquaporins increase the rate of H2 O passing (kidney and plant root cells).
Amino functional Group
Amines Polar Hydrophilic Weak bace
Noncompetitive Inhibition
An allosteric inhibitor binds at the allosteric site, changing the shape of the active site so the substrate cannot bind
Cellular Junction
Anchoring Tight Gap Plasmodesmata
Adhesion Proteins
Attach cells to neighboring cells, provide anchors for internal filaments and tubules (increase stability)
Amino Acids
Be able to tell if they are Hydrophilic or Hydrophobic (can or cannot H bond! Essential AA must be obtained from diet
Peroxisomes
Break down various substances Common in liver/kidney cells Break down stored fatty acids for energy used for growth Plant cells - modify photorespiration products (called glyoxysomes in germinating seeds) Produce hydrogen peroxide (oxidative agent) Catalase can break down hydrogen peroxide
Intracellular Circulation
Brownian motion - random particles collide Cyclosis/streaming - circular motion of cytoplasm around cell transport molecules ER - Provide channel through cytoplasm and direct passageway from plasma membrane to nuclear membrane
Beta-glucose carbohydrates
Cellulose: a structural molecule for the walls of plant cells and wood Chitin: a structural molecule in fungal cell walls & arthropod exoskeletons. Similar to cellulose but with nitrogen-containing groups attached to each β-glucose ring
Membrane Proteins
Channel Proteins Recognition Proteins Ion channels Porins Transport Proteins Adhesion Proteins Receptor Proteins
Ionic Bonds
Complete transfer of e- Very different in electronegativity NaCl
Fibronectin
Connects integrins to a collagen and proteoglycans network (transmits mechanical and chemical signals into and out of the cell) Laminin - similar to fibronectin Focal Adhesions - how cells can connect to ECM (uses actin) Hemidesmosomes - another way to connect cells to ECM (intermediate filaments - keratin) Fibroblasts - cells that produce collagen/connective tissue elements Integrins - couple ECM (outside of cell) to cytoskeleton (inside cell), involved in cell signaling, wound repair
Central Dogma
DNA -> RNA -> Protein Cannot go from Protein to RNA Prions - misfolded proteins other proteins to misfold
Nucleic acids
DNA and RNA Purines - 2 rings (Adenine and Guanine) Pyrimidines - 1 ring (Cytosine, Uracil, Thymine - CUT the PY)
Extracellular Circulation
Diffusion - can meet food and respiratory needs, used to transport materials between cells and interstitial fluid around cells Circulatory system - Required when cells are too far from the external environment (vascular system)
Passive Transport
Down concentration gradient (High to low) NO ATP Simple diffusion, osmosis, dialysis - diffusion of solutes across a SELECTIVELY PERMEABLE membrane Plasmolysis - movement of water out of a cell resulting in collapse Facilitated diffusion - spontaneous passive transport using transport proteins Countercurrent exchange - diffusion by bulk flow in opposite directions (blood and water in fish gills
Extracellular Matrix
ECM Mechanical Support, helps bind to adjacent cells Occupied by fibrous structural proteins, adhesion proteins and polysaccharides Collagen, integrin, fibronectin
Tight Junctions
Encircle each cell, sealing that prevents passage of materials between cells (ions) This ensures molecules/ions must pass through diffusion or active transport Present in animal cells (digestive tract)
Holoenzyme
Enzyme with cofactor
Apoenzyme
Enzyme without its Cofactor
Structural Protein Classification
Fibrous - insoluble, long polymer fibers/sheets - form structural components of cells (Collagen) Globular - Soluble, folded tightly, many functions (Albumin) Intermediate - Soluble, fiber shaped, many functions (Fibrinogen)
Flagella vs Cilia
Flagella - made of flagellin in bacteria (prokaryotes) Made of microtubules in eukaryotes No adhesive properties
Outer Membrane Components
Glycocalyx - Carbohydrate - Covers outer face of cell wall (bacteria) - Covers outer face of plasma membrane (animals) - Consists of glycolipids and glycoproteins - Can provide adhesive properties, barrier to infection or markers for cell to cell recognition
Hypertonic solution
Higher external solute concentration Water rushes out of the cell, causing it to shrink Plasmolysis - cytoplasm shrinks from cell wall
Hypotonic Solution
Higher internal solute concentration Water rushes into the cell, causing cell to expand and maybe burst
Cholesterol
Influences membrane fluidity (animal plasma membrane) High temp - prevents phospholipids from moving (helps maintain rigidity) Low temp - prevents excess movement (maintains fluidity) Sterols - similar but in plants Prokaryotes - hopanoids
Cellular Circulation
Intracellular Circulation Extracellular Circulation
Carbonyl Functional Group
Ketones and Aldehydes Polar Hydrophilic
Glycolipids
Like phospholipids but with a carbohydrate group instead of phosphate
Lipids
Lipids are hydrophobic molecules with multiple functions: insulation, energy storage, structure, and endocrine Triglycerides Phospholipids Steroids Adipocytes Glycolipids Transported vialipoproteins High unsat. FA = High membrane fluidity (kinks allow for fluidity) - cold temps Low unsat. FA = Low fluidity (keeps rigidity) - high temp
Microtubule Organizing Centers
MTOCs Centrioles and basal bodies (base of each flagellum and cilium in 9x3 array PLANT CELLS LACK CENTRIOLES
Microfilaments
Made of actin Involved in cell motility CLEAVAGE FURROW
Microtubules
Made of tubulin (protein) support and motility Flagella and cilia Colchicine - alkaloid that inhibits polymerization of microtubules (Mitotic poison)
Noncyclic Photophosphorylation
Making ATP from ADP and Inorganic Phosphate using energy from light 1 - e- trapped by PS2 are energized 2 - Primary e- acceptor accepts the energized e- 3- ETC - Ferredoxin and cytochrome (carrier proteins containing Iron) 4 - energized e- lose energy in ETC, which is used to phosphorylate (ADP -> ATP, approx. 1.5 ATP) 5 - ETC terminates with PS 1, e- are energized by light again and passed to another primary e- acceptor 6- e- combine w/ NADP+ to form NADPH (coenzyme) 7 - Water is split and 2 e- replace the e- PS 2 lost LIGHT DEPENDENT
Carbohydrates
Monosaccharides - single sugar molecule (glucose, fructose) Disaccharides - 2 sugar molecules joined by glycosidic linkage (sucrose, maltose) Polysaccharides - connected monosaccharides bonded via dehydration synthesis, broken by hydrolysis
Transport Proteins (Membrane)
Move substances across membrane Active - Use ATP Passive - No ATP Carrier proteins - Exposed to 1 side of membrane at a time (Bind to molecule -> change shape -> molecule passes to other side
Gap Junctions
Narrow tunnels between animal cells (formed from connexin proteins) Prevent cytoplasm of adjacent cells mixing but allow ions to pass (basically channel proteins) Present in Animal Cells - heart (allow electrical impulses to pass)
Plasmodesmata
Narrow tunnels between plant cells Desmotubules - narrow tubes of ER allowing material exchange
Endomembrane System
Network of organelles and structures (directly or indirectly connected) that functions in protein transport into or out of the cell Plasma Membrane ER Golgi apparatus Nuclear envelope Lysosomes Vacuoles Vesicles Endosomes NOT MITOCHONDRIA OR CHLOROPLASTS
Smooth ER
No ribosomes Synthesizes lipids and steroid hormones for export Liver cells - functions in toxin break down Muscle cells - SR, stores ions (Ca2+)
Nuclear Lamina
Nuclear Lamina - dense fibrillar network inside nucleus - composed of intermediate filaments and membrane associated proteins - provides mechanical support - Helps regulate DNA replication, cell division, and chromatin organization
Organelles
Nucleus Cytoplasm Cytosol Ribosomes Smooth ER Rough ER Endomembrane system Lysosomes Golgi apparatus Peroxisomes Vacuoles Mitochondria
Phosphate functional group
Organic phosphates Polar Hydrophilic Acid
Membrane Protein Classification
Peripheral - Loosely attached to one surface of the lipid bilayer Integral - Embeded inside the lipid bilayer - Transmembrane - spans entire bilayer going through both sides
Cell Walls
Plants - cellulose Fungi - chitin Protists Bacteria - peptidoglycans Provide structural support
RNA
Polymer of nucleotides containing ribose (not deoxyribose) 2' and 3' hydroxyl groups Uracil instead of Thymine Single stranded Less stable than DNA (more reactive due to extra hydroxyl group)
Proteins
Polymers of Amino Acids joined by peptide bonds
Protein Structure
Primary - AA sequence Secondary - 3D shape from H bonds (alpha helices, beta sheets) Tertiary - 3D shape of entire molecule due to non-covalent R group interactions Quaternary - 3D structure from 2+ peptide chains interacting
Ribosomes
Protein synthesis Eukaryotes - 60S + 40S = 80S Prokaryotes - 50S + 30S = 70S Free ribosomes - make proteins that function within the cytosol
Channel Proteins
Provide passage through membrane for hydrophilic substances (soluble, polar, charged)
Intermediate Filaments
Provide support for maintaining cell shape (keratin)
Denaturing Proteins
Removes Secondary, Tertiary and Quaternary structure Caused by - Excess temperature - Chemical Stress - pH change - Heavy metal salts - Radiation Loss of shape = loss of function
Rough ER
Ribosomes Creates glycoproteins by joining polysaccharides to polypeptides Eukaryotes - Continuous Makes proteins used in membrane or secreted out of the cell
RNA World Hypothesis
Self-replicating RNA was the precursor to current life Supported by: - RNA can store genetic info like DNA - RNA can catalyze chemical rxns like enzymes
Covalent Bonds
Sharing of e- Nonpolar - equal sharing of e- due to similar electronegativity Cl2 Polar - unequal sharing of e- due to different electronegativity HCl
Composition Protein Classification
Single - ONLY AA (Albumin) Conjugated - AA+non-protein components (lipoprotein, glycoprotein)
Membrane Permeability
Small, uncharged, nonpolar molecules, hydrophobic CAN FREELY PASS All other molecules need transporter (large, charged, polar)
Competitive Inhibition
Something similar to the substrate binds at the active site Can overcome by increasing substrate concentration
Adipocytes
Specialized fat cells White fat cells - large lipid droplet (mostly triglycerides), small cytoplasm Brown - small lipid, largely cytoplasm
Alpha-glucose carbohydrates
Starch - store energy in plant cells. Consists primarily of amylose and amylopectin. Glycogen - store energy in animal cells. Differs from starch in its polymer branching
Types of Proteins
Storage Transport Hormones Receptors Motion Structure Immune Defense Enzymes
Protein Classification
Structural - Fibrous - Globular - Intermediate Composition - Single - Conjugated
Sulfhydryl
Thiols
Vacuoles
Transport - move materials between organelles, or organelles and the plasma membrane Food - Temporary nutrient receptacles, merge with lysosomes to break down food Central - large, occupy much of plant cell interior, exert Turgor, specialized membrane = tonoplast Storage - in plants store starch, pigment and toxins Contractile - collect and pump out excess water to prevent bursting (active transport)
Golgi Apparatus
Transport of various substances in vesicles Cisternae - flattened sacs that modify ER products
Enzymes
Usually Globular proteins Act as catalysts (lower Ea to increase Rxn Rate) Unchanged in Rxns Efficiency determined by pH and temperature Cofactors - nonprotein molecules that assist enzymes Coenzymes (organic cofactors - vitamins)
Lysosomes
Vesicles from Golgi Contain digestive enzymes (break down nutrients, debris) function in apoptosis when they release their contents into cell autophagy (intracellular breakdown of unneeded/defective cellular components).
Other Lipid Derivatives
Waxes - esters of FA and monohydroxylic alcohols, used as protective coating or exoskeleton Carotenoids - FA carbon chains with conjugated double bonds, 6 membered rings on each end (Colored pigments in plants/animals) Porphyrins - 4 pyrrole rings, metal ion complex, Heme
Hydrogen bonding
Weak intermolecular bond when a hydrogen bonded to a highly electronegative atoms is attracted to the negative charge on another molecule HF, HO, HN can hydrogen bond
Nucleosomes
basic units of DNA Organization, 8 histones (DNA coils around little units)
Anchoring Junctions
desmosomes (keratin filaments within the cell attached to adhesion plaques joining adjacent cells together via connecting adhesion proteins) Hemidesmosomes Adherens Junctions Provide mechanical stability, hold structures together Present in animal cells that experience mechanical stress (skin, cervix, uterus)
Isotonic solution
equilibrium, everyone is happy
Nucleolus
helps produce ribosomes in the nucleus (rRNA)
Recognition Proteins
include the major-histocompatibility complex (MHC) on macrophages used to distinguish between self and foreign; Glycoproteins due to oligosaccharides attached.
Nucleoid
irregular shaped region within the cell of prokaryotes that contains all/most genetic material (prokaryotes lack a nucleus).
Nuclear Envelope
lipid bilayer that surrounds the nucleus. Nuclear pores cross the nuclear envelope for transport in/out (mRNA, ribosome subunits, nucleotides, proteins such as the RNA polymerase and histones, etc.)
Receptor Proteins
membrane proteins that bind ions and signaling molecules, causing changes on a cellular level EG - insulin receptors, ligand‑gated ion channels
Motion Proteins
movement generated at a cellular or at the level of the entire organism EG - tubulin (lagella‑cell movement), actin and myosin (skeletal muscles - organism movement)
Transport Protein (Function)
movement of substances within and between cells hemoglobin (transport oxygen), cytochromes (carry electrons)
DNA
nitrogen base, five carbon sugar deoxyribose, and a phosphate group 3' hydroxyl group 2 antiparallel strands of a double helix Backbone held by phosphodiester bonds A and T - 2 bonds C and G - 3 bonds (CG3)
Chromatin
packing structure of DNA - Heterochromatin - tightly packed - Euchromatin - loosely packed
Immune Defense Proteins
prevent and protect against pathogen attack EG - antibodies
Hormones
signaling molecules circulated throughout the body to regulate organs EG - growth hormone, prolactin, glucagon
Cytoplasm
site of metabolic activity and transport. It doesn't include nucleus, but does include cytosol, organelles, and everything suspended within the cytosol. The cytoplasm is an area, not a structure! Cytosol - Intracellular Fluid (doesn't include organelles) Cytoplasm = stew, Cytosol = broth
Structural Proteins
strengthen and support tissues EG - collagen (connective tissue), keratin (nails)
Chromosomes
tightly condensed chromatin that form for cell division