Biology G11 Semester 1

Phospholipid

Amphipathic molecule with hydrophilic head and hydrophobic tail.

Phospholipid bilayer

Double layer forming the plasma membrane structure.

Cholesterol

Amphipathic steroid that modulates membrane fluidity
1 polar OH group and hydrocarbon chains

Integral proteins

Proteins embedded in the lipid bilayer
Functions include ion channel and pump proteins

Peripheral proteins

Proteins attached to the membrane surface or integral proteins

Glycoproteins

Carbohydrate attached to a protein for cell recognition and adhesion

Glycolipids

Carbohydrate attached to a lipid for cell stability

Simple Diffusion

Passive movement from high to low solute concentration
Occurs with small, non-ionic, and lipid-soluble molecules

Osmosis

Passive water movement from low to high solute concentration

Aquaporin

Protein that facilitates water movement across membranes.

Facilitated diffusion

Passive transport following the concentration gradient through channel proteins
occurs with ions and polar molecules

Active transport

Energy-requiring movement against concentration gradients carried out by protein pumps

Protein pumps

Proteins that transport substances using ATP.

Organelles

discrete structures with specific and vital functions

Compartmentalization

Separation of cell interior into distinct areas allowing simultaneous metabolic processes

Nucleus functions

DNA replication, transcription, and mRNA modification.

Stem cells

Unspecialized cells capable of self-renewal.

Self-renew

Ability to divide and produce identical cells.

Potency

Capacity to differentiate into various cell types.

Embryonic stem cells

Pluripotent cells from early development stages

Adult stem cells

less potent cells with limited differentiation potential.

Totipotent stem cells

Can form any cell type and new organisms.

Pluripotent stem cells

Can form any body cell type from germ layers.

Multipotent stem cells

Can form a limited number of related cell types.

Stem cell niches

Sites maintaining adult stem cells for proliferation.

Bone Marrow

Location of hematopoietic stem cells for blood.

Hair follicles

Contain epidermal stem cells for skin regeneration.

Differentiation

Process where cells become specialized during development.

Embryonic Development

Zygote divides and differentiates into specialized cells.

Morphogens

Gene regulating chemicals affecting cell development.

Gene Activation

Higher morphogen concentration leads to more gene activation.

Nucleus

double membraned circular organelle with pores

Nucleolus

Site of ribosome construction within the nucleus.

Chromosomes

DNA structures associated with histone proteins.

Rough Endoplasmic Reticulum

consists of cisternae with ribosomes; synthesizes proteins.

Smooth Endoplasmic Reticulum

consists of a branched network of tubular membranes; synthesizes lipids and steroids.

Golgi Apparatus

consists of shorter, curved cisternae that processes proteins from rER for secretion.

Lysosome

Spherical organelle (formed from golgi vesicles) containing digestive enzymes.

Free Ribosomes

Cytoplasmic granules synthesizing proteins for cytoplasm.

Chloroplast

Double membrane of stacks of thylakoids that produce glucose.

Vacuoles

Large and single (plants) or few and temporary (animals) structures for storage and digestion

Vesicles

Small structures transporting materials within cells.

Microtubules

Cylindrical fibers moving chromosomes during division.

Centrioles

Anchor points for microtubules in cell division.

Water

Polar molecule essential for life processes.

Hydrogen Bond

Attraction between partially charged water molecules (partial positive H and partial negative O)

Cohesion

Water molecules stick together due to hydrogen bonds.

Adhesion

Water molecules stick to hydrophilic substances.

Surface Tension

Cohesive structure of water resisting breakage.

Hypertonic Solution

higher solute concentration, water moves to it

Hypotonic Solution

Lower solute concentration, water moves from it

Isotonic Solution

Equal solute concentration inside and outside cells, dynamic equilibrium

Condensation Reaction

Links monomers, releasing water and forming polymers.

Catabolic Reaction

Breaks down substances into simpler components, energy releasing/exergonic

Anabolic Reaction

Builds up substances from simpler units, energy requiring/endergonic

Hydrolysis Reaction

Splits water to break down polymers.

Monosaccharides

Simple sugars that cannot be further split.

Glucose

polar hexose monosaccharide (C6H12O6) that is stable, easy to transport, and yields great chemical energy.

Polysaccharides

many monomers joined by glycosidic bonds

Cellulose

B glucose sub-units linked by 1-4 glycosidic bonds
primary component of plant cell walls

Cell

Smallest unit capable of independent life.

Cell Theory

All cells arise from pre-existing cells.
All organisms are made of one or more cells
Cells are the fundamental united of life

All organisms are made up of one or more cells

Unicellular organisms

Single-celled organisms, eukaryotic or prokaryotic.

Eukaryote

Cells with a nucleus and membrane-bound organelles. 80S Ribosomes

Prokaryote

Cells without a nucleus, DNA in cytoplasm. 70S ribosomes, cell wall made of peptidoglycan

Homeostasis

Maintenance of constant internal environment.

Metabolism

Sum of all biochemical reactions in organisms.

Nutrition

Supply of nutrients for energy, growth, and repair

Excretion

Removal of metabolic waste products

Growth

Increase in cell size or number.

Response to Stimuli

Perception and reaction to environmental changes.

Reproduction

Production of offspring, sexual or asexual.

Resolution

Degree of visible detail in an image

Magnification

the degree of enlargement

Compound Light Microscope

Uses multiple lenses to compound levels of magnification.

Electron Microscope

Uses electrons to magnify specimens.

Scanning Electron Microscope

Creates 3D images of specimen surfaces.

Transmission Electron Microscope

Creates 2D images of internal structures.

Freeze Fracture

rapid freezing and fracture technique to observe specimen planes.

Cryogenic Technique

Freezes specimens at low temperature to avoid ice crystal and artificial structure formation.

Immunofluorescence

Uses fluorescent dye to identify targets.

Lipids

composed of hydrocarbon chains or rings, non-polar and hydrophobic

Hydrophobic properties

Lipids do not dissolve in water.

Simple Lipids

esters of fatty acids and an alcohol, Include waxes and triglycerides

Compound Lipids

Esters of fatty acids and alcohol linked to additional groups for function, includes phospholipids and glycolipids

Derived Lipids

hydrolysis of simple/compound lipids, includes steroids and cholesterol

Fatty Acids

Long hydrocarbon chains in most lipids, except steroids

Saturated Fatty Acids

No double bonds, maximum hydrogen atoms.

Unsaturated Fatty Acids

Contain one or more double bonds.

Essential Amino Acids

Cannot be produced, must be ingested.

Non-essential Amino Acids

Produced by the body from other amino acids, not diet-dependent.

Conditional Amino Acids

produced by body at different times (pregnancy, infancy, illness)

Amino Acids

monomers composed of a central alpha carbon, amine group, carboxyl group, variable group, and hydrogen atom

Peptide Bond

Bond between amine and carboxyl groups.

Polypeptides

Chains of amino acids not yet functional.

Denaturation

Loss of protein structure and function.

Enzymes

Biological catalysts speeding up reactions.

Substrates

Reactants in enzyme-catalyzed reactions.

Krebs Cycle

Necessary pathway in cellular respiration = used to produce NADH/ATP.