Characteristics of Living Things

• All living things share specific characteristics, ranging from cellular organization to the ability to adapt.

Cellular Organization

• Life is cellular, with organisms being either unicellular, colonial, or multicellular.

Response to Stimuli

• Organisms respond to physical (light), chemical (oxygen), and biological stimuli, often to enhance survival and reproduction.
• For example, plants respond to caterpillars by synthesizing volatile attractants to recruit parasitoid wasps.

Reproduction

• Reproduction, whether asexual or sexual, is vital for the continuation of a species.
• Each form of reproduction has advantages and disadvantages.

Adaptation and Natural Selection

• Species adapt through genetic variations arising from mutations, meiosis, and random fertilization.
• Individuals with beneficial adaptations tend to survive and reproduce more successfully in their environment (natural selection).

Growth and Development

• Growth involves an increase in mass, while development encompasses physiological, structural, and functional maturation.

Regulation

• Organisms maintain internal variables like temperature, blood pressure, and oxygen within a specific range through homeostasis, often via negative feedback mechanisms.

Metabolism

• All organisms require matter to release energy for metabolism.
• Autotrophs produce their own organic matter.
• Heterotrophs consume organic matter.

Atoms and Their Properties

• Atoms are the basic units of matter, consisting of protons, neutrons, and electrons.
• Protons and neutrons reside in the nucleus, contributing to the atom's mass.
• Electrons orbit the nucleus and have minimal mass.
• The first electron shell can hold a maximmum of 2 electrons
• Other shells have a maximum capacity of 8 electrons.
• An atom's reactivity depends on the number of electrons in its valence shell; atoms with less than the maximum number of electrons in their valence shell are reactive.
• Valence refers to the number of unpaired valence electrons, determining the number of bonds an atom can form (e.g., hydrogen can form one bond, oxygen can form two).

Chemical Bonds

• Atoms with incomplete valence shells interact to achieve stability by forming ionic bonds through electron donation/acceptance, resulting in charged ions (cations and anions).
• E.g., NaCl with sodium as the cation and chloride as the anion
• Covalent bonds involve electron sharing and are prevalent in cellular structures, with bond strength increasing with the number of shared electron pairs.
• Compounds consist of two or more atoms of different elements bonded ionically or covalently.
• Molecules are the result of covalently bonded atoms.

Polarity in Covalent Bonds

• Equal electron sharing results in nonpolar covalent bonds.
• Unequal sharing creates polar covalent bonds with slightly positive and negative charges.

Hydrogen Bonds

• Hydrogen bonds form when a positively charged hydrogen atom is attracted to a negatively charged atom in another molecule.
• Although individually weak, their cumulative effect is biologically significant, influencing water's properties and DNA structure.

Organic Molecules

• Organic molecules, essential for life, consist of carbon atoms covalently bonded to other elements.
• Molecules composed of only carbon and hydrogen are called hydrocarbons.
• Carbon's valence of 4 allows for many bonding patterns.

Properties of Organic Molecules

• The properties depend on the hydrocarbon skeleton (nonpolar) and functional groups involved in chemical reactions.
• Functional Groups: Carboxyl, Phosphate, Amino, Methyl, Hydroxyl, Sulthydryl, Carbonyl or Aldehyde
• Small structural variations in functional groups can lead to significant differences in properties and functions of molecules like testosterone and estradiol.

Macromolecules and Polymers

• There are 4 main types of organic molecules: Carbohydrates, proteins, lipids, nucleic acids.
• Except for lipids, biological macromolecules (polymers) are formed through dehydration reactions that bond smaller molecules (monomers).
• Water, facilitated by enzymes, breaks covalent bonds between monomers through hydrolysis.

Carbohydrates

• Carbohydrates are hydrates because for every C (carbon) there is 1 H2O (water molecule)
• Carbohydrates are a major fuel source and structural component, and are important for identification and cellular communication.
• Monosaccharides (simple sugars) are carbon rings with polar functional groups, forming rings in aqueous solutions.
• Disaccharides and polysaccharides form through dehydration reactions, creating glycosidic bonds.

Polysaccharides

• These consist of more than two simple sugar monomers.
• Starch is a polysaccharide and plants use it for as an energy store. It's composed of amylose and amylopectin.
• Glycogen is a polysaccharide that can be found in animals' liver and muscle. Hydrolysis of glycogen leads to the output of glucose. It is similar to amylpectin, however glycogen has more branching
• Cellulose is a polysaccharide that plants use providing structure to their cell walls.
• Chitin is a polysaccharide that animals use for structural support in invertibrates. Chitin's also found to have nitrogen.

Lipids

• They function as storage, insulation and for cushioning. If they're oil/fat, they are solid/liquid respectively in room temperature.
• They're hydrocarbon skeletons that are nonpolar and hydrophobic
• There are three different types of Lipids: triglycerides, phospholipids and steroids
• Triglycerides: Dehydration between glycerol and 3 fatty acid chains leads to the produce of water molecules and triglycerides.
• Saturated: No double bonds between the carbons makes the maximum number of hydrogens can be found. They are solid in room temperature, and often found in animal fats, which can lead to the inside of blood being deposited.
• Unsaturated: As they have double bonds between some carbons (which could be plant fats), the triglycerides don't pack as well and are liquids at room temperature.

Monounsaturated/Polyunsaturated Fats, Isomers

• Monounsaturated Fats: Has one double bond in fatty acid
• Polyunsaturated Fats: Has multiple double bonds in fatty acid. these are "essential" and cannot be synthesized by the body and is required (e.g. plasma membranes, nerves, blood clotting.
• Isomers: compounds has the same molecular formula but will have different shapes and different functions
• Structural isomers have different bonding patterns.
• Cis-Trans isomers have the same bonding patters, with same side (cis) or opposite sides (trans). Cis-Fatty acids are liquids, while saturated and trans unsaturated fats are solids at room temperature.

Other Lipids: Fats

• Saturated and trans unsaturated fats can artificially be made during hydrogenation.
• Partially Hydrogenating: Converts cis-unsaturated fats to trans unsaturated fats (solid at room temperature)
• Concerns about the contribution of saturated and trans unsaturated fatty acids leading to heart disease led to the Ministry of Health in Canada to prevent trans unsaturated fats form all Canadian foods to prevent these concerns.

Other Lipids: Phospholipids

• They're two fatty acids, with a glycerol molecule which attached to a phosphate group.
• The phosphate head is polar and hydrophilic while the fatty acid tails are nonpolar and hydrophobic. Thus they're amphipathic as one side consists of both hydrophobic/hydrophilic

Steroids

• These lipids have a carbon skeleton, which consists of four rings
• Amphipathic cholesterol is found in the membranes of the plasma (PM). The fluid is modulated by the cholesterol where a hydrogen of -OH associates heads, hydrophobic associates tails of PM.
• Hormones are signalling and will move via a body; estradiol & testosterone

Diversity

• Proteins: Has diversity of forms, resulting a diversity of functions
• Enzymatic, Defensive, Storage, Transport, Hormonal, Receptor, Contractile, Structural
• The monomers are amino acids. They are organic. molecules with carboxyl & amino grouping.
• The amino acids differ property wise in due to the differing side chains (R groups). Also, determines acid's chain reactivity
• The polar side chains react/interact w/ anything of polar/charged, electrically. Chain wise, so will those that are electrically charged and can be considered polar wise. (Can be hydrophilic to some extent)
• Side Chains: Acidic, Basic, Hydrophilic or Hydrophobic

Proteins: Bonds

• Di (2 bound) -Polypeptides (>2 amino) Produced during dehydration (covalent bonds created)
• The type/order/number determines peptide reactivity

Proteins: Structure/Function

• Molecule is biologically functional-twisted, coiled (unique form/function)

• Contains at 1+ polypeptide chains

• Structure is how sequence is in amino acid of Polypeptide chain

• Secondary Structures- coils (a-helix folds) / pleated Beta chains (h-bonding between constituents of polypeptide, those that aren't groups)

• Structure "Tertiary" 3-d, interaction- inter- various groups (R-side) form h-bond, bonds like "ionic", or if sulfide (R side= exteriors )

• Groups "hydrophobic" in interior (R side) can cause side exteriors because disruptions can cause the "denaturation"

• Quaternary/Multiple polypeptide chains interact /form proteins

Nucleid Acids and DNA/RNA

• Function to Express/transmit/store hereditary information

• DNA stores heredity (Genes make a long sequence as chains to make the genes, as chains make chromosomes) Many genes code AA sequence

• RNA carries the building seq, for proteins that DNA build the sequences.

• The monomer in nucleic "Nucleotides"

• The carbon has the "pentose", meaning that in DNA it's Ribose, in RNA it's deoxyribose. The group, called Phosphate is included too

• Nucleobases

• Five total, Adenine, Thymine, Guanine or Cytosine are made, but if its in RNA< only Uracil occurs (NO THYMINE)

• They (nucleobases) made d/h reaaction, covalent formed. Has bonds that are called PHOSPHODIESTER

Double Stranded DNA Nucleotide Chains

• DNA is double stranded chain -The sequence that make code for acids have specific pairing traits from the strand with N bases codes for (those)
• The Single Nucleic ones/chains WITHNOO Thymine can be said as "RNA" and only have U (uracil).

Cells: Basics

• Cell/microscope = Cell Theory (Allowed scientists can view, leading that all organic (Life) that have a basic form in cell, also basic life)
• DNA instruction can be found in all the common cells the shared strc:
• Cells - DNA has "Instruct"
• All cells: ribosomes are protein machinery.
• Cytoplasms-bound to plasma, Cy is mainly fluids as component "water" Eukaryo are cytoplasm if the Nucleus in clud . plasma membrane. (The latter part is Phospholipid bilayer)
• They can be in bacteria, Archaea , or Eukaryotic

Pro/Eykarotic cells

• Pro (nucleus -bef) Unicellular (cell wall w pepdioglyycan. Lack cells w "nucleus" or enclosed
• Double stranded DNA. Chromsmes (circular and 1 bound to nucleiod) surface append
• EYK- "normal " nucleus multi/uniceel (wall"
• Multi linear "chromes" Oganelles-all have membrane Ribsomes er series Mito

Organells (EU) Types

• Nucleus, protects, has "DNA". Nuclear envelope membranes around with a nucleus

System - Membrane, organelles with transportation, production that connect Nucleuar enve, ER, ly, vesicles that transfer

Endoplasmic "Reticulum" ER

Surface Ribo (smooth) functions Synthesize lipids Metabolize and "Detoxif"

Stores ions (cals) , Smooth Reticulum Rough Re has surface ribosomes. Major funtion is for glycol and Poly synthesis/peptides can (thread the Er) carbones can form with proteins that Lumen the are glycoptoreins with transfer.

Cell Other parts

• Ribosomes the are tiny from Rib RNA/Protein (made), chains assemble from messe transcript RNA
• Apparatus Golgi- the membrane can pack the lipids/proteins in the end and SER the (Via Veslics will sort/package in materials will go transfered in vessel for macro molecs also)
• Transport the , membrane Sac they bud from ERS Golgi the "vesicle” is transfer (smol ) vacoule = bigger in store also to food

Cell: Lys/mitochon

• "Lysomes" -special vesicles in diges enzymes main act to break the macros down
• Mitochdria_ double membrane (ben-shaped), with membranes in inner crests" has " intermembrane space. Matrix, has respirate (the Cellular) & produce TP (Happen Major)

Cells: Chlor and Other

• double bonded" - in plant/algae,

• "Thylkaloid’s are sacs in flat membrane stack Photosythetic can absorb with membranes that are pigment

• Endosymbol- eukaryotes will arise

Oxygen nonPhoto will enguluf - Mito will engulgf photo to be engufl- to make chlorophyll

Cytohseske - pro in network (the fibers) to go cyto main has functions that does

• Cell will keep "shape"" Movement/ anchor in"

• Cillia : Pro fibres, surface outer (plant don'tl) air-liquid will contract Flagella" _ used (pro that are loner ) is for Rotate -pro