Solutions, Diffusion, and Osmosis

• Solutions consist of a solvent (fluid) and a solute (dissolved particles).
• Diffusion is a passive process where particles move from areas of high to low concentration.
• Osmosis is the diffusion of water across a selectively permeable membrane.
• Hypertonic solutions have a higher solute concentration; isotonic solutions have equal solute concentrations; hypotonic solutions have lower solute concentrations.
• Cells in hypotonic solutions can swell and burst; cells in hypertonic solutions can shrink and die.
• Facilitated diffusion uses membrane proteins to move large or charged materials.
• Channel-mediated passive transport allows specific solutes to pass through membrane tunnels.
• Carrier-mediated passive transport involves membrane proteins that bind to a solute, change shape, and release it on the other side.
• Protein pumps use ATP to actively transport molecules across the cell membrane.
• Endocytosis is the process where the plasma membrane traps extracellular material and brings it into the cell in a vesicle.
• Receptor-mediated endocytosis is triggered by surface receptors attaching to specific substances.
• Phagocytosis is "cell eating" where the cell takes in solids.
• Pinocytosis is "cell drinking" where the cell takes in liquids.
• Exocytosis releases large molecules from the cell within membranous vesicles.
• Passive transport mechanisms include simple diffusion, osmosis, and facilitated diffusion.
• Passive transport moves material from high to low concentration.
• Active transport mechanisms include sodium-potassium pumps, endocytosis, and exocytosis.
• Active transport moves material from low to high concentration.
• Enzymes are biological catalysts that lower activation energy needed for a reaction.
• Catalysts speed up chemical reactions.
• Activation energy is the energy needed to start a reaction. Enzymes reduce this energy.
• Enzymes are usually proteins.
• The active site on an enzyme binds to the substrate (reactant) molecule.
• Enzymes can be reused after a chemical reaction.
• Allosteric effectors change the shape of the enzyme molecule, thereby affecting enzyme action. Examples are temperature, pH, radiation, cofactors, and end products of metabolic pathways.
• Feedback inhibition uses cofactors as an "off" switch for enzymes, providing negative feedback.
• Enzymes can speed up a chemical reaction in both directions.
• Cellular respiration is the breakdown of glucose to make ATP.
• Anaerobic respiration occurs without oxygen, while aerobic respiration requires oxygen.
• Cellular respiration has three main stages: glycolysis, citric acid cycle, and electron transport system.
• Glycolysis occurs in the cytoplasm and breaks down glucose.
• The citric acid cycle occurs in the mitochondria and breaks C-C bonds to create NADH & FADH2 (electron carriers), releasing CO2.
• The electron transport system produces ATP, IF oxygen is present.
• Overall reaction for glycolysis: Glucose + 2 ATP -> 4 ATP + 2 NADH + 2 Pyruvate
• Result/reaction for the citric acid cycle: 2 Pyruvic acid → 2 NADH + 2 Acetyl-CoA as the molecule enters the mitochondria, then 2 Acetyl-CoA → 2ATP + 6 NADH + 2 FADH2

Electron Transport Chain

• Electrons are transported along a chain causing pumping of protons (H plus) to the intermembrane space.
• A gene codes for one RNA molecule, which may be translated into one polypeptide (protein).
• Transcription is the process where RNA forms along a segment of one strand of DNA.
• Messenger RNA (mRNA) is a copy of the code for a polypeptide (protein).
• mRNA is created by RNA polymerase decoding DNA to synthesize mRNA during transcription.
• Introns are non-coding sections of a DNA or RNA molecule; exons are coding sections.
• Translation uses mRNA to make a protein, occurring in the cytoplasm at the ribosome where mRNA codons are used to put amino acids in order.
• A codon is a set of 3 nitrogen bases (nucleotides) on mRNA.
• Ribosomal RNA (rRNA) is a part of ribosomes.
• Transfer RNA (tRNA) carries amino acids to a specific mRNA codon at the ribosome during translation.
• The ribosome is the location of translation.
• The start codon is AUG.
• During interphase: G1 is for normal growth; S is for DNA synthesis; G2 is for growth.
• Telomeres are noncoding, protective segments of DNA at the ends of a chromosome.
• Mitosis is division of the nucleus to form identical copies.
• Prophase: nucleus disappears; chromatin forms into chromosomes; centrioles attach to chromosomes.
• Metaphase: chromosomes move to the middle of the cell.
• Anaphase: chromatids are pulled apart, and cytokinesis begins.
• Telophase: chromatids are pulled to each part of the cell, the cell starts to pinch apart, and cytokinesis finishes.
• Cytokinesis is the division of the cytoplasm, occurring in anaphase and telophase.
• Meiosis occurs only in sexual organs, producing unique cells with half the genetic content.
• A tissue is a group of cells that perform a common function.
• The four developed tissue types are epithelial, connective, muscle, and nervous tissue.
• Connective tissue is the most abundant/widespread tissue type.
• The three nonspecialized tissue types in the embryo are endoderm, mesoderm, and ectoderm.
• The extracellular matrix is a nonliving fluid material between cells, providing support and communication.
• Collagen gives strength and durability, while elastin provides stretchiness. Repair
• Regenerated tissue results from phagocytic cells removing dead or injured cells.
• Scar tissue is connective tissue that replaces muscle/nervous tissue.
• Epithelial and connective tissues have the greatest ability to regenerate.
• A neoplasm is any abnormal cell growth.
• Benign neoplasms grow slowly and are less likely to spread; malignant neoplasms grow fast and are likely to spread.
• Neoplasms of epithelial tissue are called "carcinomas"; neoplasms of connective tissue are called "sarcomas".
• Factors that may lead to cancer: genetic factors, carcinogens, age, and metabolic factors.
• Methods of detecting cancer include self-examination, medical imaging, blood tests, and biopsy.
• Common cancer therapies include chemotherapy, radiation therapy, laser therapy, and immunotherapy.
• The five general functions of epithelial tissue are protection, sensory functions, secretion, absorption, and excretion.
• The two basic types of epithelial tissue are membranous and glandular.
• The basement membrane is connective tissue under the membrane.
• Epithelial tissue is typically avascular.
• Squamous cells are flat; cuboidal cells are cubed; columnar cells are taller than they are wide; pseudostratified columnar cells look irregular.
• Simple epithelium is a single layer; stratified epithelium has many layers.
• Simple squamous epithelium: absorption or secretion; one layer of flat cells, alveoli in the lungs- sac where gas exchange occurs.
• Simple cuboidal epithelium: in glands and ducts; one cell layer of cube shaped cells.
• Simple columnar epithelium- in digestive system; single layer of tall, column shaped cells; such as goblet cells (mucus secreting), cilia (movement), and microvilli (absorption).
• Simple pseudostratified columnar: in airways; motile cilia and mucus are important modifications.
• Stratified cuboidal epithelium: two or more rows of cells are typical; basement membrane is indistinct; located in sweat gland ducts and pharynx.
• Stratified columnar epithelium: rare- located in segments of male urethra and near anus.
• Nonkeratinized Stratified squamous epithelium: lines the vagina, mouth, and esophagus; free surface is moist; primary function is protection.
• Keratinized Stratified squamous epithelium: multiple layers of flat,squamous cells; cells filled with keratin; covers outer skin on body surface.
• Transitional epithelium: changes shape when stretched; urinary bladder.
• A goblet cell (AKA mucous gland) is a mucus-secreting cell; found in simple columnar epithelium and pseudostratified columnar.
• Keratin provides extra protection and waterproofing.
• Exocrine glands discharge secretions into ducts, Endocrine glands make hormones; secrete without ducts to surrounding fluids (pituitary, thyroid, and adrenal glands).
• Apocrine glands secrete through small pieces of cell that leaves with chemicals (milk, puberty sweat).
• Holocrine glands secrete by the whole cells leaving with chemicals (oil glands).
• Merocrine glands secrete chemicals without cell destruction (saliva, normal sweat).
• The four general functions of connective tissue are connects, supports, transports, and protects.
• The four major categories of connective tissue are fibrous, bone, cartilage, and blood.
• Loose fibrous (areolar): fibroblasts and macrophages; between tissues and organs to bind them together.
• Adipose: adipocytes; acts as food reserve, support, protection, heat generation, and insulation; produces the hormone leptin, which signals the brain concerning how much fat is stored.
• Reticular: tissue that forms the framework for the spleen, lymph nodes and bone marrow- immune system.
• Dense irregular: fibers intertwined irregularly to form a thick mat.
• Dense regular: bundles of fibers are arranged in regular parallel rows.
• Collagenous dense regular fibrous CT: tendons (muscle to bone) and ligaments (bone to bone).
• Fibroblasts are cells that make fibers in CT.
• Adipocytes are fat cells; fibrous connective tissue.
• Brown fat is used to produce heat; found in infants to help contribute to heat as they develop muscles.
• The major cell type in bone (osseous) tissue is osteocytes.
• The five functions of bones: Support, Protection, Point of attachment for muscles, Reservoir for minerals, Supports blood-forming tissue.
• The osteon (haversian system) is the structural unit of bone
• Central canal: blood vessel in middle.
• Lamellae: rings around the central canal.
• Lacuna: holes containing cells (osteocytes).
• Canaliculi: cracks between lacuna and the central canal.
• Cancellous (spongy) bone has lacuna and osteocytes.
• Trabeculae: thin beams of bone.
• Spongy Like appearance.
• Contains red bone marrow.
• Red bone marrow forms blood cells.
• Cell type in cartilage is chondrocytes; avascular.
• Perichondrium: membrane surrounds cartilage.
• Hyaline cartilage: most common type; in nose and end of bones.
• Fibrocartilage: strongest; shock absorption; lots of fibers; intervertebral disks (backbone) and pubic symphysis (holds public bones together).
• Elastic: lots of elastin (stretchy); found in external ear and voice box.
• Most abundant cartilage: hyaline.
• Strongest cartilage: fibrocartilage.
• Blood is only liquid tissue; no fibers.
• Blood plasma is Liquid fraction (of blood; Makes up 55% of total blood volume.
• The three formed elements of blood: Red blood cells, White blood cells, Platelets.
• The four functions of blood: Transportation, Regulation of body temperature, Regulation of body pH, White blood cells destroy bacteria.
• The three types of muscle: Skeletal, Smooth and Cardiac.
• Skeletal: striated voluntary muscle tissue; bone; multiple nuclei.
• Smooth: nonstriated;involuntary;muscle tissue;digestive tract; one nucleus.
• Cardiac: striated involuntary muscle tissue; heart; one nucleus.
• Intercalated disks are gap junctions that help conduct electricity from one cell to the next.
• Function of the nervous tissue: Excitable: ability to make electric impulses, Conductivity: ability to carry electric impulses. Nervous Tissue Brain: processing center, Spinal cord: relay station, Nerves: wires that move electricity around.
• A neuron has: Dendrite (one or more): receives info, Cell body,or soma: contains nucleus, Axon (single process): carries electricity, Ends in axon terminals/synaptic knobs: sends signal to target.
• The neuron is the conducting unit of the system
• Neuroglia are Special connecting, supporting,, and coordinating cells that surround neurons.
• The skin is the largest organ.
• Integument and cutaneous membrane are other names for the skin.
• The two layers of the skin: Epidermis and Dermis.
• Thin skin has hair and a smooth surface; most common.
• Thick skin has no hair and a ridged surface; thicker epidermis.
• Thick mostly found in: Palms, fingertips, soles of feet.
• Keratinocytes: make keratin (protein in skin cells which protects them from drying out) in skin and hair and nails.
• Melanocytes: make melanin (pigment gives skin/hair color).
• Dendritic cells: play a role in immune response- protection from invaders. Tactile epithelial cells (merkel cells): receptors for light touch, Lamellar corpuscles: for deep pressure.
• Layers of the epidermis, from top to bottom: Stratum corneum: dead cells (gets shed), Stratum lucidum: only in thick skin, Stratum granulosum: makes keratin, Stratum spinosum: cells start to stretch and connect to each other to make a network of cells.
• Stratum basale: divides to produces new cells.
• Stratum lucideum is not in thin skin.
• The functions of the dermis: Gives strength to the skin-anchors skin to body, Serves as a reservoir storage area for water and electrolytes.
• The two layers of the dermis: Papillary layer and Reticular layer.
• Papillary layer is more superficial: thin bumps called papillae, loose fibrous CT.
• Reticular layer: dense irregular CT with lots of collagen and some elastin.
• Arrector pili muscles: attached to hair, Makes hair stand erect- “goosebumps”; involuntary.
• Hypodermis: also called Subcutaneous layer or superficial fascia; not part of the skin.
• The melanin pigment is made by melanocytes.
• Two types of melanin: Eumelanin: dark brown, Pheomelanin: reddish-orange.
• Albinism is a mutation that stops melanin production.
• Factors that affect melanin production: radiation exposure, Heredity (DNA).
• The functions of melanin: Forms protective cap on nucleus of keratinocytes to protect them from UV light.
• Beta carotene: orange pigment.
• Hemoglobin: red pigment.
• Cyanosis: blue pigment.
• Cyanosis: Oxygen poor blood.
• Function of Surface film: Antibacterial, lubrication, hydration of skin, buffer, blockage.
• The seven functions of the skin: Protection, Vitamin D production, Sensation, Flexibility, Excretion, Immunity, Body temperature homeostasis.
• The hypothalamus regulates body temperature.
• Get rid of heat by: Evaporation and blood flow.
• The types of Hair from the body: Lanugo: before birth, Vellus: after birth on most of body, Terminal: after birth; axilla, pubic hair, beard hair.
• Hair follicle structure that hair grows from. All hair strands are created here.
• Male pattern baldness: Results from a combination of a genetic tendency, and male sex hormones (tendency to become bald).
• Melanin makes hair have different colors.
• Hair turns white: from melanocytes not working as much.
• Hair and nails is made of the protein called Keratin.