Protein Function and Dynamics

• These are study notes for Lectures 1-7, and Chapters 2-7.

Atoms

• Atoms are composed of subatomic particles.
• Neutrons have no charge and a mass of 1.7x10^-24g, equivalent to 1 Dalton or 1 atomic mass unit (amu).
• Protons have a positive charge and the same mass as neutrons (1 Dalton or 1 amu).
• Electrons have a negative charge and a negligible mass of about 1/1000 amu.
• The nucleus is composed of protons and neutrons and has a positive charge.
• Electrons orbit the nucleus and are kept close by its positive charge, creating the atom's structure.

Elements

• The most abundant elements in living systems are hydrogen, oxygen, nitrogen, and carbon.
• Of the 92 naturally occurring elements, 25 are required for human health, while plants need only 17.
• Oxygen, carbon, hydrogen, and nitrogen make up 96% of living matter.
• Trace elements are required in very minute amounts, with iron being necessary for all life forms.

Electrons and Chemical Bonds

• Atoms with incomplete valence electrons can form chemical bonds by sharing electrons with another atom.

Radioactive Isotopes

• Radioactive isotopes spontaneously release subatomic particles, emitting energy and particles.
• Radioactive decay leads to changes in the atom and radiation emission.
• Cytotoxic agents are radioactive isotopes used to kill cancer cells.
• Radioactive isotopes can be used as biological tracers to track molecules in organisms.
• They can also be used for DNA mutation studies in the lab, like deletions, to study gene roles.

Chemical Bonds

• A covalent bond involves the sharing of a pair of valence electrons between two atoms.
• Nonpolar covalent bonds have electrons equally distant from both nuclei.
• Polar covalent bonds have electrons shifted towards the more electronegative atom.
  • Examples include Hydrogen (N.P. single bond), Oxygen (N.P. double bond), Water (2 P. single bonds), and Methane (4 N.P. single bonds).
• Ionic bonds occur when the electronegativity difference between atoms is so large that electrons are stripped from the less electronegative atom.
• This results in two oppositely charged ions: cations (+) and anions (-).
• Cations and anions form a strong attraction.
• Ionic compounds, or salts, form strong bonds in dry environments but weaken in wet environments.

Weak bonds

• Covalent bonds are the strongest.
• Weak bonds are next.
• Hydrogen bonds form when a hydrogen atom covalently bonded to one electronegative atom is attracted to another.
• Van der Waals interactions occur when uncharged (nonpolar) molecules develop transient charges due to random electron movement.
  • Electrons accumulate in 'hot spots' on the molecule, causing attraction.
  • Gecko's toe hairs adhering to a wall are an example.

Water Molecules

• Water has unique properties due to hydrogen bonding.
• Cohesion is the capacity of water molecules to stick together in liquid H2O, results in high surface tension.
• Bugs walk on water as an example.
• Adhesion allows water to cling to dissimilar surfaces and rise upwards, as seen in trees.
• Water stabilizes temperatures because it has high specific heat, requiring a large amount of heat to change temperature; this is a factor in ice formation.
• Water expands when freezing, making liquid water denser than solid water.
• Decreased density is less mass per volume.
• Ice floats because it has a lower density.
• An increased number of hydrogen bonds in ice keeps molecules further apart, leading to lower density.
• Water is most dense at 4 degrees Celsius.
• Water is a versatile solvent due to its polar bonds.
• Solutions are homogeneous mixtures of substances.
• Hydrophilic molecules dissolve or absorb in water due to polar bonds, like ionic compounds (salts) and polar substances (sugars).
  • A solute is a dissolved substance.
• Hydrophobic molecules do not dissolve or absorb in water because they have nonpolar bonds.
• Dehydration reactions assemble polymers, and hydrolysis reactions break polymers apart.

Molarity

• Molarity measures the number of moles per liter of solution.
  • In the instance of 1L of 2 Molar NaCl, 116.88 grams are needed.

Acids, Bases, and Buffers

• Acids increase [H+] and bases increase [OH-].
• The pH scale ranges from 0-14, indicating acidity or alkalinity.
  • Solutions with a pH from 0-7 are acidic and donate H+ ions.
  • Most biological solutions range from 6-8, like gastric juice, with a pH of 2.
  • Solutions with a pH from 8-14 are alkaline and donate OH- ions.
• Buffers minimize changes by absorbing or donating protons.
  • They usually consist of weak acids and conjugate bases.
  • In blood, carbonic acid acts as a buffer; when pH increases, the reaction donates protons, and when pH decreases, the reaction accepts protons.

Functional Groups

• Functional groups include hydroxyl (-OH), carbonyl (-CO), carboxyl (-COOH), amino (-NH2), sulfhydryl (-SH/HS), phosphate (-OPO32-), and methyl (-CH3).
  • Hydroxyl and carbonyl groups are polar; carboxyl and amino groups have a +/- charge.
  • Sulfhydryl groups are polar and form S-S bonds, phosphate groups are charged and bulky, and methyl groups are non-polar.
    • Alcohols contain hydroxyl groups (e.g., ethanol), aldehydes/ketones contain carbonyl groups (e.g., acetone, propanal), carboxylic acids contain carboxyl groups (e.g., acetic acid), amines contain amino groups (e.g., glycine), thiols contain sulfhydryl groups (e.g., cysteine), organic phosphates contain phosphate groups (e.g., glycerol phosphate and ATP), and methylated compounds contain methyl groups (e.g., 5-methylcytosine).

Macromolecules

• A polymer is made of similar building blocks
• Large polymers are macromolecules, composed of repeating monomer units:
  • Carbohydrates: Simple sugars
  • Nucleic acids: Nucleotides
  • Proteins: Amino acids
  • Lipids: Fatty acids

Carbohydrates

• These include sugars and are the simplest carbs/monosaccharides.
  • They have a carbon/oxygen/hydrogen ratio of 1:2:1 (CH2O).
  • Glucose (C6H12O6) supplies energy through cellular respiration and structural component of cell walls.
• Carbohydrates create chitin for insect exoskeletons and form complexes that include glycolipids and glycoproteins.
• Polysaccharides are carbohydrate macromolecules made of simple sugar building blocks.
• Polysaccharides don’t necessarily follow the same molecular ratios as monosaccharides (e.g., sucrose C10H22O11).
• Starches (plants) and glycogen (animals) store glucose via polysaccharide storage structures.
• Cellulose is a tough wall component in plant cells.

Lipids

• Lipids don't include true polymers
• They are primarily hydrophobic hydrocarbon regions
• The basic subunit of lipid = fatty acid

Fatty acids

• Have carboxyl groups attached to a long carbon skeleton
• Sources of energy that are greater than glucose
• Parts of phospholipids and fats

Fats

• Fats derive from glycerol + fatty acids.
• Three fatty acids join glycerol by ester linkage to form a triglyceride.
• Fatty acids in a fat can be the same, or different.
  • Saturated fats have chains with no double bonds
  • Unsaturated fats have chains with double bonds

Phospholipids

• Unsaturated fatty acid chains often have a bend.
• The bend in the cell prevents close packing of phospholipids in the membrane.
• Phospholipids have a hydrophilic head and hydrophobic tails (group together).
• When added to H20, they self-assemble:
  • Into micelles, single layer sphere
  • Liposomes, double layered sphere
  • And bilayers, double layered sheets
• At the cell surface, phospholipids arrange in a bilayer with hydrophobic tails towards the interior.

Phospholipid membrane

• Phospholipid bilayer forms a boundary between the external and cell environment.

Sterols

• Sterols area lipid class with lipids that are characterized by a carbon skeleton + 4 fused rings.
• Sterols include cholesterol and its derivatives.
• Plasma membrane components contribute to membrane fluidity/rigidity because of their structure.
• Sterols are precursors to steroid hormones.

Nucleic Acids

• Nucleic acids are made of monomers called nucleotides and polymers called polynucleotides. A nucleotide has a nitrogenous base, pentose sugar, and 1+ phosphate groups.
• There are two types: DNA and RNA
  • DNA is deoxyribonucleic acid.
  • RNA is ribonucleic acid. DNA provides directions for its own replication. DNA also directs synthesis of messenger RNA (mRNA), a process called gene expression.
• There are two families of nitrogenous bases: purines and pyrimidines. Pyrimidines, like cytosine, thymine, and uracil, have a 6-membered ring Purines, like adenine and guanine, have 6-membered rings fused to a 5-membered ring.
• Sugars come as ribose (oxygen at position 2) for RNA and deoxyribose (no oxygen at position 2) for DNA.
• Nucleosides consist of a nitrogenous base + sugar, with the sugar attached to a base at carbon 1.
• Carbons 3 & 5 are functionally important for creating polymers.

DNA and RNA

• RNA has the base Uracil.
  • And lacks methyl group at position 5.
• DNA has the Thymine base and both share purine bases.
• To form a polymer nucleic acid, nucleosides become nucleotides.
• Nucleotides are phosphate esters of nucleoside- esterification occurs at position 5 on sugar, nucleoside - 5' - phosphate = nucleotide.
• Nucleotides function as energy carriers (ATP, GTP), signals (cyclic AMP), and subunits of DNA and RNA.
• DNA is a polymer of nucleotides with constant phosphate and sugar backbones and variable bases.
• DNA molecules have 2 polynucleotides spiraling around an imaginary axis, forming a double helix
• DNA backbones run in directions, is antiparallel: i.e. 5' 3' with a 5' end having a free phosphate group and a 3' end with w/ a free hydroxyl group.

Base Pairing

• Complementary base pairing occurs where adenine (A) pairs with thymine (T) with 2 hydrogen bonds.
• And guanine (G) pairs with cystine (C) with 3 hydrogen bonds.
• Complementary base pairing allows:
  • information preservation during DNA replication
  • template for mistake repair
  • transfer of information (during transcription & translation)
  • complementary pairing that can occur between 2 RNA molecules or between parts of the same molecule
• RNA can form many shapes and is integral to protein synthesis.

Nucleic Acid functions

• Nucleic acids store genetic information (DNA).
• They also transfer genetic information (mRNA) from structural components that fold into a specific shape, like ribosomal RNA, rRNA.
• Nucleic acids have enzymatic activity (ribozymes) & regulation of gene expression (microRNA, miRNA, and short interfering RNA, siRNA).

Polymers and Monomers

• There are four macromolecules: carbs, proteins, lipids, and nucleic acids.
• The monomers are:
  • Simple sugars are carbs, such as glucose and fructose which form complex sugars that include starch like cellulose (in plants)
  • Proteins, with amino acids that form polypeptides
  • Lipids, with fatty acids and glycerol that becomes triacylglycerol (fat), phospholipids, sterols, an cholesterol
  • And nucleic acids, whose nucleotides become DNA,RNA

Molecule structure

• Structure determines function
  • Carbs have CHO
  • Proteins have CHON and central carbon, carboxyl + amino groups on ends, side chain (R group)
  • Lipids have CHO and log chains of C.
  • Nucleic acids have CHOMP.
• Functionally:
  • Carbs provide energy
  • Proteins have enzymes with catalysts
  • Lipids are hormones, aid in energy processing, cell structure.
  • Nucleic Acids act as a genetic code

Transcribing DNA to RNA

• Amplifying the gene signal, central dogma is DNA to RNA to Protein
• Transcription = process of creating DNA -> RNA.
• Translation = process of creating RNA -> protein.

Types of RNA

• messenger RNA (mRNA) encodes protein.
• transfer RNA (tRNA) transfers adaptor between mRNA and amino acids.
• ribosomal RNA (rRNA) forms ribosome.
• small nuclear RNA (snRNA) supports the functions that occur in various nuclear processes (splicing).
• small nucleolar RNA (snoRNA) facilitates chemical modification of RNA's.
• micro RNA (miRNA) regulates gene expression.
• short interfering RNA (siRNA) silences gene expression.
• long non-coding RNA (lncRNA) regulates gene expression.

Translation

• Translation of tRNA anticodon is complementary to mRNA sequence
• Read in sets of 3 nucleotides + codons encodes for amino acids- 64 possible 3 nucleotide combinations
• 3 codes for protein termination are stop codons
• Ribosomes binds to mRNA and recruits correct tRNA for mRNA sequence + reads genetic code
• Ribosomes are mad of 100 proteins + RNA
• tRNA bring amino acid corresponding to their anticodon to ribosome and there it can join the growing protein chain
• Correct reading frame = open reading frame (ORF)
• Start codon = methionine (AUG)

Reading frame

Amino acids: Correct reading frame = open reading frame (ORF)

• Start codon = methionine (AUG)
• Stop codons = UAA, UAG, UGA
• Organic molecules w/ amino & carboxyl groups. Differ in their varying properties, due to the different properties of their chains, R groups.
• Amino acids Each amino acid has a name, with a 3 letter and a 1 letter abbreviation.
• Nonpolar and Hydrophobic: Glycine (Gly/G), Alanine (Ala/A), Valine (Val/V), Leucine (Leu/L), Isoleucine (Lle/l), Methionine (Met/M), Phenylalanine (Phe or F), Tryptophan (Trp or W), Proline (Pro/P)
• Polar & Hydrophilic: Serine (Ser/S), Threonine (Thr/T), Cysteine (Cys/S), Tyrosine (Tyr or S), Asparagine (AsnN), Glutamine (Gln/Q)
• Charged. & Hydrophilic: Aspartic acid (Asp/D, ACIDIC), Glutamic acid (Glu/E, ACIDIC), Lysine (Lys/K, BASIC), Arginine (Arg/R, BASIC), Histidine (His/H, BASIC)

Polypeptide formation

• Polypeptide formation is the creation of polymers of amino acids that form a functional protein.
• Specific activities of proteins result from their intricate + 3-dimensional structure and one or more polypeptides precisely twisted, folded, and coiled into a unique shape
• Sequence of amino acids determines a protein's 3-dimensional structures
• A protein's structure determines how it works

Levels of Protein Organization

• Primary = sequence of amino acids
• Secondary = sequence of amino acids folded into a 3-dimensional shape αlpha helix (H bond every 4th peptide bond).
• Tertiary: A mature protein folds upon itself.
• Quaternary: A protein consisting of greater than 2 polypeptide chains that form 1 macromolecule
• Physical + chemical conditions can affect its structure.

Protein Denaturation and Representation

• pH alterations, salt concentration, temperature, etc. can cause a protein to unravel.
• Loss of a protein's native structure as a molecular structure of proteins denatures it.
• Ways of representation:
  • Atoms, protein backbone, space filling, and simplified models
• Proteins are the Most abundant macromolecule in cells.

Enzymatic Proteins

• Proteins that speed up chemical reactions are enzymes.

Protein Functions

• Protein has several types of functions. Defense, such as immune response. Storage for energy. Helping transport nutrients among the cells. Improving cellular communication between cells. Movement of cells. Structural Support of cells.
• Defensive Proteins: Disease proteins that identify bacteria and viruses as antigens to antibodies.
• Storage proteins is an amino acids' storage in a cell. Ex: casein a milk protein providing amino acids for baby mammals.
• Transport proteins are used for substance movement in cell such as Sodium channels that move sodium ions into specific cell compartments.
• Hormonal proteins signal entire organism for organism wide signalling coordination, insulin is an example because it provides blood sugar regulation..
• Receptor proteins triggers cell responses by detecting chemical stimuli such as hormones, peptides, and or steroids.
• Motor Proteins are used in the contraction of muscles and the coordination of movement.
• Support the shape of cells and give shape to an organism such as collagen which provides connective tissues in animals.

Cells

• The basic features of cells are plasma membrane, semifluid substance (cytosol), chromosomes (carry genes), and robosomes (make proteins).

Prokaryotes and Eukaryotes

• Prokaryotes lack a nucleus are are 1-5 microns in size (bacteria and Archea).
• Eukaryotes have a nucleus and are and are 10-100 microns in size (proteins, fungi, animals, and plants).

Membrane Differences

• Eukaryotes are compartmentalized.
• Eukaryotic cells also have proteins.
• Fungi, animals, and plants.
• A selective barrier that allows sufficient passage of oxygen nutrients, and waste to service the volume of every cell is created by the plasma membrane, and the surface area to volume ratio is critical for this to work.
• Cells are small because they maintain that critical surface area to volume ratio.
• Need to interact w/ their environment. Absorb nutrients and remove waste. Volume increases more quickly than surface area, placing limits on Metabolic requirements on cell. Multicellular organisms addresses the volume to surface ratio problem by creating groups of small cells that assemble into something bigger
• In prokaryotic cells, there is no nucleus or membrane or membrane-bound organelles, there is cytoplasm bound by plasma membrane, and no DNA in unbound region (nucleoid).
• However there are ribosomes present.

Compartmentalization.

• A eukaryotic cell includes the organelles + internal membranes that divide the cell into compartments for optimal transport conditions.
• Animal cells have a double layer of phospholipids and most of the same organelles with a centrosome, microvilli/cilia..
• Plant cells have Cell walls, chloroplasts, a big central vacuole, and plasmodesmata.
• To study cells, microscopy is used but there are parameters to abide too

Different Microscope types

• Light passes through a specimen and then through glass lenses.
• Lenses refract (bend) the light for a magnified image.
• Light microscopes can magnify up to 1000x size of actual specimen.
• Highest resolution is around 200 nm.
• Enable cell components to be stained/labeled to improve contrast.
• Fluorescent markers label individual cells to improve detail.

Super Resolution

• Confocal microscopy removes out of focus light and provides sharper images of 3-dimensional tissues and cells.
• Super Resolution Microscopy exceeds 200 nm resolution.
• Lowest can go to: 20 nm Through computational/mechanical processes
• An electron Microscope can then be used for subcellular structures
• Scanning electron microscopes (SEM's) provide 3-D images
• Transmission electron microscopes (TEM'S) can focus a beam of electrons through a thin section of a specimen.
• Cryogenic Electron Microscopes preserves of specimens + allows visualization of structures in their cellular environment, w/o need for preservatives at low temperatures by Studying protein structures and using cryogenic electron tomography (cryoET)
• Taking cells apart and separating major organelles from one another through centrifuging.
• Biochemistry and cytology help correlate cell function w/ stricture
• The nucleus Contains most of cell's genes and is the most visible organelle. Enclosed and separated from the other components by a double membrane nuclear envelope (each membrane consists of a lipid bilayer). Lines with protein nuclear side lamina.
• Nuclear DNA units organized into chromosomes associated with proteins to make chromatin
• Chromatin condenses to form discrete molecules as cell prepares to divide.

Ribosomes

• Complexes made of rRNA & protein.
• Build proteins in cytosol and ER membrane or nuclear envelope

The Endomembrane System

• The Endomembrane System includes the Nuclear envelope, ER, Golgi apparatus, Lysosomes, Vacuoles, with Plasma membrane.
• Vesicles are small bound sacs that transport cell components
• There are a plethora of organelle types. Smooth ER lacks ribosomes but synthesizes lipids, detoxifies drugs and poisons, and stores calcium ions. On the other hand, the rough produces proteins. (glycoprotein – covalently bonded to carbs), secreted proteins, membrane proteins). Distributes transport vesicles and secretes proteins surrounded by membranes to memorize cell factory.
• The Golgi Apparatus consists of flattened membrane sacs that Modify ER products Manufacturer certain macromolecules Stores and packages materials into transport vesicles, transports protein through vesicles. Cis face receives vesicles from ER. Trans face ships out vesicles to cytosol. Consists of flattened membrane sacs functions to Transport proteins through vesicles.
• A lysosome is a membranous sac of hydrolytic enzyme.

Lysosomes & Endoctyosis

• Lysosomal enzymes work best in the acidic environment inside lysosome
• Lysosomes are made by rough ER with the Golgi apparatus and some arise from budding from trans face of Golgi apparatus
• Endocytosis involves the process of taking matter into a living cell by forming a food vacuole, and engulfs large particles through a process called phagocytosis.A lysosome fuses w/ food vacuole digests the contents from it. Lysosomeres can be used to recycle the cell's own organelles and macro molecules.
• Autophagy breaks down old parts for new ones.

Vacuole

• Vacuoles are large vesicles from the ER & Golgi apparatus/endocytosis.
• Central Vacuoles are only include in plant cells. Has storage for inorganic ions, K and Cl and has sap for growth and waste removal.
• Food ( formed by endocytosis/phagocytosis after cells bring matter into cell ) and contractile ( found in fresh water particles, pumps excess water ) also form some vacuoles

Mitochondria & Chloroplasts

• Mitochondria is the site of cellular respiration, to generate ATP, in eukaryotic cells. Includes a smooth outer membrane. inner membrane folded into cistae.
• Inner Membrane contains two intermembrane space and mitochondrial matrix, called Dynamic Mitochondria Networks, for some metabolic steps of cellular respiration and enzymes that synthesize ATP.
• Mitochondria divides and fuse to create to forming the dynamic networks. In similar process, chloroplasts use green pigment chlorophyll, as well as enzymes and other molecules in photosynthesis Internal organization: Thylakoids are membranous secs staked to form granum.

Membrane types and Endosymbiosis

• Both Mitochondria and Chloroplasts are similar to bacteria, enveloped by a double membrane and they both have free ribosomes with similar DNA structures.
• They Grow and reproduces somewhat independently in cells based on Endosymbiont Theory.
• Early progenitor of Eukaryotes engulfed progenitoric organisms in form what we now know what has become the Host cell which Endosymbiont.
• Endosymbiont has evolved from the Mitochondria and Chloroplasts.
• Peroxisomes are oxidative organelles that include enzymes that transfer H atoms from substrates to oxygen, H2O2 converted to H2O that forms unknown relation to other organelles and are are specialized metabolic compartments by a single membrane.

Cytoskeleton

• A network of fibers extends throughout cytoplasm.
• It organizes cell's structures and activities, anchors many organelles and maintains cellular shape through 3 molecular structures

The Molecular Structures

• Microtubules which are the thickest, (25 nm w/ 15 nm lumen) and the hollow tubes are formed by tublin and their fuctions is to maintain cell shape, cell motility, chromosome movement, and to grow out of Centrisome(in animal cells) near nucleus with pair of centrioles.
• Microfillaments are intertwined strands of actin that are thinnest (7 nm) and functions is to maintain cell shapes, cell changes, muscle contraction, cytoplasmic streaming (plant cells), cell motility, cell division (animal cells).
• Intermediate Filaments is a type if fiber that's diametrically, in the mid range range (8-12 nm) and itincludes keratin, with afunction to Maintain cell shape, anchorage of nucleus + other organelles and form nuclear lamina.

Cili and Flagellum

• Control beating of flagella and cilia but differing in their beating patterns
• Flagella direction in swimming motion.
• Cilia direction is the direction that organism can move.
• Share a common structure.
• Group of microtubules sheathed in an extension of plasma membrane.
• 9 doublets of microtubules arranged in a ring + 2 single centered microtubules - Basal body anchors cilium/flagellum
• Motor protein, dynein, drives bending movements of a cilia/flagellum rather than sliding because microtubules are held in place.
• Protein domains act as feet, one maintains contact, other releases + reattaches 1 step further

Lect 6, Extra cellular Matrix (ECM) and Cell Walls

• For Plant cells,prokaryotes, fungi, and some protists Protecs shape, provides maintenance, and prevents excessive uptake of water
• Made of cellulose embedded in other polysaccharides and protein which has Layers such as Primary cell wall, Middle lamelia (Thin layer between primary walls and Secondary cell wall: In some cells, added between plasma membrane and primary cell walls for plasmodesmata
• In ECMs, cells have water and small soIutes and channels that connects plants.

ECM (Extracellular matric)

• Instead of cell walls, animals have an elaborate ECM.
• Made up of glycoproteins such as collagen, and fibronectin.
• Also ECM Proteins in plasma membrane is where Cell Recognition molecules trigger the actions need to take take place on molecule surface Glycoproteins and has Function Markers/for the structure.

Cell function

• In cell recognition, cells bind to water/solutes and communicate directly.
• Cell membranes composed of phospholipids, other lipids, proteins and carbohydrates that are aphipathic molecules, regions of a protein are are oriented toward cytosol and the extracellular fluid.

Cell membranes

• Cells recognize and bind to each other. Cells membranes are primarily phospholipids that compose of carbohydrates with aphipathic molecules that are used to communicate inside and outside the membrane, in a water and solute solvent mixture,
• The hydrophobic regions are embedded in the bilayer + fluid mosaic
• Depicts that the membrane has different functions.

Protein

• Protein is not randomly distributed in the membrane.
• It is primarily held together by weak hydrophobic interactions + most lipids an some protein that can move side ways as temperture decreases.
• It's mosty depends in the layer type since many rich fats are more rich than fatty acids that membranes must work properly
• -At lower body temp, cholesterol maintains movement of phospholipids (more fluidity/less flexibility) since Membranes must be fluid to work properly+ have fluid affects on permeability and movement of protein.

Membrane Proteins

• Consist of proteins on the plasma membrane on the outer layer that determine the membrane’s functionality with different cellular composition amongst various Cells
  • Have multiple types such as Peripheral: for bound to surface + Integral proteins that penetrate the hydrophobic core Types include transmembrane proteins like aquaporins that allow to incraese water, and Channel used in the tunnel to transport

Select Perms, Transport Types, and Diffusion

• Nonpolar hyrophobic compounds dissolve and pass through the cell
• Hydro phillic and Polar substances are usually impeded
• The transport will use Channel to tunnel. and protein
• Diffusion of a substance across a biological membrane with help of chemical energy