KIN 268 Final Exam

Chemical reactions

Chemical reactions

new bonds form and old ones break

Forms of energy

potential (stored e.g. calories), kinetic (motion), chemical (bonds)

Metabolism

all the body’s chemical reactions

Law of conservation of energy

energy can be converted but no created/destroyed; energy at start (reactants) = energy at end (products)

Catalyst

lower activation energy to speed up reactions e.g. enzymes

Activation energy

initial energy needed to start reaction and break bonds

Exergonic/exothermic reactions

energy released > energy absorbed

Endergonic/endothermic reactions

energy released < energy absorbed

Coupled reaction

energy released by exergonic reaction fuels endergonic reaction

Anabolism

all the body’s synthesis reactions where ions, atoms, and molecules combine to form large molecules

Catabolism

all the body’s decomposition reactions where large molecules split into ions, atoms, molecules

Inorganic compounds

simple molecules that lack carbon e.g. water (most abundant [55-60%] and important), acids, bases, salts

Organic compounds

contain carbon, hydrogen, and covalent bounds (38-43%)

Carbohydrates

main source of chemical energy, 2-3%, CHO e.g. glycogen, starch, sugars, cellulose

Monosaccharides

simple sugars, 3-7 carbon atoms e.g. glucose (blood sugar), fructose (fruits), galactose (milk sugar), deoxyribose, ribose

Disaccharides

combination of 2 monosaccharides by dehydration synthesis e.g. sucrose = glucose + fructose, lactose = glucose + galactose, maltose = glucose + glucose

Polysaccharides

tens to hundreds of monosaccharides e.g. glycogen (stored carbs in animals), starch (stored carbs in plants and food), cellulose (indigestible fibre, plant cell walls, helps eliminate feces)

Lipids

18-25%, CHO

Fatty acids

make up triglycerides and phospholipids; break down to generate ATP; saturated or unsaturated

Triglycerides

major lipid form in body/food; glycerol backbone and three fatty acids; fats and oils; protect, insulate, and store energy (unlimited)

Phospholipids

major component of cell membranes; 2 fatty acids and glycerol backbone connected to N-containing charged group by phosphate group

Health benefits of omega 3 fatty acids

decrease inflammation, increase muscle protein synthesis, oxygen to heart during exercise, and nerve conduction velocity e.g. polyunsaturated (flax, canola oil, olive oil, seafood), EPA, DHA, ALA

Steroid: Cholesterol

minor component of all animal cell membranes; make up bile salts, vitamin D, and steroid hormones

Steroid: Bile salts

needed to digest and absorb dietary lipids

Steroid: Vitamin D

help regulate calcium level; bone growth and repair

Steroid: Adrenocortical hormones

help regulate metabolism, resistance to stress, and salt and water balance

Steroid: Sex hormones (testosterone, estrogen)

stimulate reproductive functions and sex characteristics

Eicosanoids (prostaglandins, leukotrienes)

modify responses to hormones, blood clotting, inflammation, immunity, stomach acid secretion, airway diameter, lipid breakdown, and smooth muscle contraction

Carotenes

synthesize vitamin A (used to make visual pigments in eye); antioxidants

Vitamin E

promotes wound healing, prevents tissue scarring, contributes to normal structure and function of nervous system; antioxidants

Vitamin K

required for synthesis of blood-clotting proteins

Lipoproteins

transport lipids in blood, carry triglycerides and cholesterol to tissues, remove excess cholesterol from blood

Amino acids

central carbon atom bound to a hydrogen atom, an amino group, an acid group, and a unique side chain (HASA)

Amino acid pool

all available amino acids in the body and tissues

Protein turnover

continuous synthesis and breakdown of protein

Protein

structural, regulate processes, immunity, assist in muscle contraction, transport substances, and serve as enzymes; 1+ polypeptide chains folded into a 3D shape (determines its function).

Polypeptides

10+ amino acids combined

DNA

nucleic acid that represents the inherited genetic code for making proteins in nuclei, regulates most cell activity, self-replicating

RNA

nucleic acid that carries genetic code and assists in making proteins

Nucleotide

pentose sugar, nitrogenous base, phosphate group

Adenosine triphosphate

main energy-storing molecule in the body; energy currency

Cellular respiration

catabolism of carbs, lipids, and proteins; releases energy to attach phosphate to ADP to produce ATP

Anaerobic cellular respiration

in the absence of oxygen, glucose partially breaks down into pyruvic acid; yields 2 ATP

Aerobic cellular respiration

in the presence of oxygen, glucose, lipids and protein completely breaks down into CO2 and H2O; yields 32 ATP

Plasma membrane

flexible, sturdy barrier surrounding the cytoplasm; fluid mosaic model: sea of lipids and different proteins; selectively permeable

Nucleus

consists of the cell’s DNA in chromosome (DNA-protein complex) and genes (hereditary units); double membrane bilayer

Nucleolus

cluster of DNA, RNA, and proteins that produce ribosomes

Chromosomes

condensed DNA and histone protein complex that provides structural support for DNA; where genes are arranged

Gene expression

a gene’s DNA is used as a template through transcription, translation, and protein synthesis

Membrane proteins (RIC ELM)

either integral/transmembrane or peripheral; ion channel, carrier, receptor, linker, enzyme, identity marker

Membrane lipids

phospholipids, glycolipids, cholesterol

Cholesterol

stabilizes membrane and reduces fluidity

Concentration gradient

difference in chemical concentration on either side of the membrane

Electrical gradient

difference in ionic concentration on either side of the membrane

Electrochemical gradient

gradients combine to help move substances across the plasma membrane

Passive process: Simple diffusion

movement of compounds from an area of high to low concentration; does not require energy e.g. Vit E, fatty acids; “downhill”

Passive process: Facilitated diffusion

transmembrane proteins help large polar or charged solutes move through the lipid bilayer

Channel-mediated facilitated diffusion

movement of a solute down its concentration gradient across the lipid bilayer through a membrane channel protein; most are for ions (2K+out, 3Na+ in)

Carrier-mediated facilitated diffusion

movement of a solute down its concentration gradient across the lipid bilayer with the help of a carrier transport protein

Passive process: Osmosis

net movement of water through a selectively permeable membrane by simple diffusion or aquaporin channels from an area of high to low solvent concentration (low to high solute concentration); does not require energy

Tonicity

how a solution influences the shape of body cells

Active process: Active transport

movement of substances from a low to high concentration; requires energy (ATP) e.g. glucose, amino acids; carrier proteins change shape to pump a substance across a plasma membrane against its concentration gradient; “uphill”

Cytoplasm

cytosol (intracellular fluid 75-90% water, 55% cell volume) and organelles (specialized structures with shapes and functions excl. nucleus)

Cytoskeleton

helps determine the cell shape; aids in movement, absorption, support, attaching cells; microfilament, intermediate filaments, microtubules

Cilia

hairlike projections that extend from the cell’s surface; oar moving through water; moves fluid along surface; sweep away foreign particles that could interfere with proper cell function

Flagella

motile projection of the cell; longer than cilia; move an entire cell e.g. forward motion of sperm

Ribosomes

granules of protein and RNA found in nucleoli, free in the cytosol, and on rough ER; directed to assemble amino acids into proteins by mRNA which specifies the genetic code copied from DNA

Transciption

in the nucleus, genetic info encoded in a strand of DNA is copied onto mRNA to direct protein synthesis

Promoter and terminator

part of DNA where transcription begins and ends

mRNA

directs protein synthesis through codons (segments of 3 nucleotides specific for certain amino acids)

rRNA

joins with ribosomal proteins to make ribosomes

tRNA

binds to amino acid and holds it in place on a ribosome until it’s incorporated into a protein during translation

Translation

in the cytosol, the ribosome reads the mRNA nucleotide sequence to determine the amino acid sequence of the forming protein while tRNA attaches the amino acids

Rough ER

parallel, flattened membranous sacs covered with ribosomes (protein synthesis); continuous with nuclear membrane; creates membrane, cytosolic, organellar, and secretory proteins

Smooth ER

extends from the rough ER; lack ribosomes; involved in synthesis of fatty acids and steroid hormones (testosterone, estrogen), glucose metabolism, and muscle contraction (sarcoplasmic reticulum form)

Golgi complex

forms lysosomes which function via 60 digestive and hydrolytic enzymes and perform autophagy (digest worn-out cells) and autolysis (destroy entire cell)

Peroxisomes

contain enzymes that use oxygen to oxidize/break down organic and toxic substances e.g. alcohol (similar to lysosome)

Proteasomes

barrel-shaped structures that destroy unneeded, damaged, or faulty proteins by cutting long proteins into smaller peptides that proteases can break down into individual amino acids; they are recycled into functional, healthy proteins

Mitochondria

site of ATP synthesis by enzymes on cristae from energy extracted from carbs, lipids, proteins, alcohol; contain ribosomes and a small circular DNA molecule (mtDNA)

Telomeres

repetitive DNA sequences at the ends of human chromosomes; regulate how many times a cell divides; shorten each time DNA replicates

Cancer

abnormal and uncontrolled multiplication of cells; may spread to other parts of the body via the bloodstream or lymphatic system

Tumour

mass of tissue that serves no physiological purpose; benign (enclosed in a membrane that prevents penetration of other tissues) or malignant (invades surrounding tissues)

Metastasis

spread of cancer; primary tumour attaches to a blood vessel or lymph node; once cancer cells are attached, they pass through the lining of the vessel move into the circulation system, spread to other parts of the body, colonize other organs

Carcinomas

starts in epithelium (cover body surface or line internal organs); most common: skin (melanoma), breast, uterus, prostate, lungs, GI, etc.

Sarcoma

starts in supporting or connective tissues e.g. bones, muscle, blood vessels

Leukemia

starts in blood-forming tissues/cells e.g. bone marrow, lymph nodes, spleen

Lymphoma

starts in cells of the lymph nodes; victims are susceptible to infection (antigens, foreign particles)

Tissue

group of cells with a common embryonic origin and function that carry out specialized activities together

Cell junctions

points of contact between the plasma membrane of cells where cells are held to form tissues

Tight junctions

transmembrane proteins that seal off passageways between adjacent cells (bladder, stomach)

Adhering junctions

contain plaque that attaches to microfilaments and membrane proteins; join cells by cadherins (glycoproteins); help resist cell separation during muscle activity (food passing GI tract)

Plaque

dense protein layer in plasma membrane

Desmosomes

contain plaque that attaches to membrane proteins containing keratin; involved in skin structure and cardia muscle; prevent cells from spreading (epidermis of skin)

Hemidesmosomes

anchor cells to basement membrane (link epithelium to connective tissue; assists in healing and regenerating tissue; involved in satellite cell activity in sections of muscle)

Gap junctions

tiny fluid-filled openings that connect nearby cells; allows molecules to pass from one cell to the other; communication mechanism between cells

Epithelial tissue

densely packed cells arranged in sheets; no spaces between plasma membranes; avascular; nerve supply; protects, secretes, absorbs and excretes; many cell junctions; attach to basement membrane

Surface epithelial tissue

forms skin and some organs, inner lining of blood vessels, ducts, body cavities

Glandular epithelial tissue

makes up portions of gland

Simple epithelium

one layer; involved in osmosis and diffusion

Pseudostratified epithelium

appear to have multiple layers; involved in absorption