Bio 30S Test 1
Homeostasis - The ability of the body to maintain a constant internal balance
What conditions do cells need to work properly? - Proper temperature (37℃), water level, pH level, and glucose concentration
Negative Feedback Loop - a mechanism that keeps the body in a consistent environment (Ex, blood sugar and temperature control)
Positive Feedback Loop - The body keeps amplifying the response and rapidly speeding up the process. (Ex: Child birth)
Components of the Negative feedback loop - Receptor -> Control Centre -> Effector ->
What keeps the body warm/cool? - Vasoconstriction and piloerection keep the body warm. Vasodilation and sweating keep the body cool.
Vasodilation - capillaries under the skin fill with blood to let out heat into the air, making your skin red and warm
Sweating - When your body is hot, your sweat glands are stimulated to release sweat. The heat from your skin evaporates the sweat, cooling the body down.
Vasoconstriction - Capillaries under the skin shut off, trapping heat in the body
Piloerection/Goosebumps - Hairs trap a layer of air next to the skin, which is warmed by body heat. The air becomes an insulating layer.
What happens to excess glucose? - It is converted to glycogen in the liver.
What hormones regulate glucose levels? - Insulin and Glucagon
Function of Glucogen - When there is a lack of glucose in the blood, glycogen is converted back into glucose
Function of Insulin - Moves glucose from the bloodstream to cells to make energy, and prevents the buildup of glucose.
How do body systems coordinate to maintain homeostasis? - The nervous system instructs the body on how to act, controlling homeostasis.
Robert Hooke - Discovered Cells, coined the name cell, and only saw dead cells.
Anton van Leeuwenhoek - Discovered Living cells
Principles of Cell Theory -
All living organisms are composed of cells.
The cell is the basic unit of life.
All cells come from pre-existing cells.
Basic Features of all Cells - Plasma membrane, Cytosol, chromosomes, ribosomes
Plasma Membrane - Thin, flexible wall, controls what enters and leaves the cell, protects the cell from its surroundings. A selective barrier allows the passage of oxygen, nutrients, and waste.
Cytosol - Fluid that fills the cells in between organelles
Chromosomes - Carry genetic information
Ribosomes - Use information from the nucleus to make proteins
Types of cells - Prokaryotic and Eukaryotic
Prokaryotic Cell - No nucleus, DNA lies free in cytoplasm, no membrane-bound organelles, always single-celled organisms.
Eukaryotic Cell - DNA in nucleus, membrane-bound organelles, Cytoplasm between nucleus and plasma membrane, larger.
Nucleus - Organelle, the membrane of the cell, holds DNA.
Mitochondria - The powerhouse of the cell, break down glucose to create energy
Endoplasmic Reticulum (ER) - A network of membranes around the nuclear envelope. A transportation system within the cell.
Rough Endoplasmic Reticulum (RER) - ER studded with ribosomes for protein synthesis
Smooth Endoplasmic Reticulum (SER) - ER without ribosomes, involved in lipid synthesis and detoxification
Golgi Apparatus - made up of flat membranous sacs called cisternae. Packages proteins and other molecules for transport to the cell membrane and to other organelles. Produces vesicles with enzymes for digestion (lysosomes)
Phospholipid Bilayer - a double layer of phospholipids that makes up the plasma membrane and organelle membranes.
Membrane Proteins - Proteins attached or embedded in the plasma membrane. Functions: Communication, Transport
Selective Permeability - Some molecules are allowed through the membrane while others are not
Effect of cholesterol on the cell membrane - Keeps the cell membrane fluid. It prevents it from becoming too fluid at high temperatures and too rigid at low temperatures.
Passive transport - The movement of substances across a cell membrane without the use of cellular energy. Moves from an area of higher concentration to an area of lower concentration.
Simple Diffusion - the passive movement of small, non-polar molecules across a cell membrane from an area of high concentration to an area of low concentration. No energy is used.
Facilitated Diffusion - cell transport where molecules move across a membrane down their concentration gradient with the help of specific transport proteins. (e.g. channel proteins, carrier proteins)
Osmosis - The passive movement of water across a semipermeable membrane from an area of high concentration to an area of low concentration.
Active Transport - Moves against a concentration gradient, requires ATP, and is performed by proteins in the membrane.
Concentration Gradient - the difference in the concentration of a substance between two areas, which causes diffusion.
Cell Membrane - a semipermeable boundary that separates the cell from its external environment
Tonicity - A solution's ability to change a cell's volume by altering its water content with osmosis
Isotonic - a solution with the same solute concentration as another solution
Hypertonic - describes a solution with a higher solute concentration than another solution, like the cell's internal environment
Hypotonic - a solution with a lower solute concentration than the inside of a cell, causing water to move into the cell via osmosis
Sodium Potassium Pump - The sodium potassium pump rests open on the intracellular part of the cell, with room for 3 sodium ions. When the sodium ions bind to the pump, ATP will power it by transferring its phosphate to the pump, turning the pump around to the extracellular side. The sodium is released, and 2 potassium ions bind to the pump. The phosphate is released from the pump, flipping around and releasing the potassium into the cell. The cycle repeats.
What determines the rate of diffusion: temperature, concentration gradient, surface area, and distance
Monomer - Building Blocks, connected by dehydration, a section of protein
Polymer - Monomers combined to make a polymer.
What are the 4 Biomolecules? - Carbs, Lipids, Proteins, and Nucleic Acids
Carbohydrates - Sugars, Starches, etc., water-soluble, quick energy source, easy to break down.
Monosaccharides- Simple Sugar Monomer
Polysaccharides - Long chains of Sugars (Ex, Glycogen in animals and Starch in plants)
Lactose - Glucose + Galactose
Maltose - Glucose + Glucose
Sucrose (Table Sugar) - Glucose + Fructose
Lipids/fats - Oils, fats, waxes, phospholipids. Stores energy in the body, chemical messengers (Ex, Steroids)
Types of Fats - Saturated and unsaturated
Saturated Fats - No double bonds in Carbon, saturated with hydrogen, can stack to become solid. Solid at room temperature (Ex, butter, animal
fat)
Unsaturated Fats - One or more double bonds causing bends in the chain, liquid at room temperature (Ex, oils), healthier than saturated fats.
Proteins - Made up of one or more polypeptide chains\
Poly Peptide Chain - A polymer of amino acids linked by peptide bonds, most poly peptides have more than 100 amino acids
Proteins in Cells - Cells contain up to 10,000 different proteins, each with a unique function.
Essential amino acids - Amino acids that can not be produced in the body
Non-essential amino acids - Amino acids that can be produced in the body
Water Soluble - Can be dissolved in water
ATP - Energy that fuels cells, powers active transport
Primary Protein Structure - Linear Sequence of amino acids in a polypeptide chain
Nucleic Acids - Biological molecules that carry genetic information (Ex: DNA, RNA)
Nucleotide - Building blocks of Nucleic Acids, contains nitrogen base, phosphate group, and a pentose sugar (Ex: deoxyribose, ribose)
Roles of Nucleotides - Store DNA and RNA, Cell signaling, Energy Transfer and Motabelism
Cell signaling - cAMP (Cyclic AMP) acts as a second messenger in cell communication
DNA - Sugar: Deoxyribose, double helix structure
Nitrogen Base: DNA - Purines: Adenine (A) and Guanine (G). Pyrimidines: Cytosine (C) and Thymine (T).
RNA - Sugar: Ribose, single strand structure, has Uracil (U) instead of (T)
Phospholipids - A type of lipid molecule that forms the essential barrier of cell membranes
Hydrophilic Areas - A region of a molecule or a surface that has an affinity for water, attracting and interacting with it
Hydrophobic areas - Regions that repel water and are nonpolar, meaning they are not attracted to water molecules
Cholesterol - A lipid, fat-like substance essential for building healthy cells, making hormones (like steroid hormones and sex hormones), vitamin D, and bile acids for digestion