Final A+P Multiple Choice Pt.2

Cell Organelles

• Nucleus: Controls cell activities, regulates gene expression, synthesizes RNA.
• rER (Rough Endoplasmic Reticulum): Site of protein synthesis.
• SER (Smooth Endoplasmic Reticulum): Synthesizes lipids, detoxifies toxins, stores calcium ions.
• Mitochondria: Produces ATP, the cell's energy currency.
• Golgi apparatus: Modifies, sorts, and packages proteins & lipids.
• Lysosome: Digests macromolecules and microorganisms, removes damaged proteins.
• Centrosomes: Organizes microtubules, facilitates cell division.
• Proteosomes: Degrades unneeded or damaged proteins.
• Cytoskeleton: Provides structural support, facilitates movement.

Ribosomes

• Synthesize proteins that are used within the cytosol.
• Ribosomes (free) transport materials or secrete substances, digest materials.

Homeostasis

• Maintains a stable internal environment, even when external conditions change.
• Regulates body temperature, blood glucose levels, etc.
• Positive feedback amplifies changes, moving them further from the initial state; examples include blood clotting, childbirth.
• Negative feedback returns a variable to its set point, counteracts a change, examples include regulating body temperature.

Atoms and Elements

• Atoms are the smallest particle of a substance and cannot be broken chemically.
• Atoms contain protons, neutrons, and electrons.
• Elements are simple substances made of one type of atom that cannot be broken down into smaller pieces.
• All atoms of the same element have the same number of protons.

Organic and Inorganic Compounds

• Organic compounds contain carbon and are part of living organisms; examples include sugars, carbohydrates, proteins, lipids, nucleic acids.
• Inorganic compounds do not contain carbon and are often found in non-living matter; examples include water, salts, acids, and bases.

Metabolism and Cellular Respiration

• Metabolism is all chemical reactions inside a living organism.
• Cellular respiration is a metabolic pathway that breaks down glucose to produce ATP.
• Cellular respiration has 4 stages: glycolysis, intermediate stage, citric acid cycle, and the electron transport chain.

Anabolism and Catabolism

• Anabolism involves building larger molecules from smaller molecules.
• Catabolism involves breaking down larger molecules into smaller molecules.

Organization of Living Things

• Levels from smallest to largest: chemical, cellular, tissue, organ, organ system, organismal.

Body Systems

• Integumentary: protection, sensation, temperature regulation.
• Skeletal: support, movement, and protection.
• Muscular: produces body movements.
• Nervous: controls muscles and some glands.
• Endocrine: secretes hormones to control digestive processes, reproductive function, and homeostasis.
• Cardiovascular: delivers oxygen, nutrients, and hormones, transports and filters lymph.
• Respiratory: exchanges gases between blood and air.
• Urinary: filters blood and removes waste products.
• Digestive: digests, absorbs, and expels products.
• Male Reproductive: produces sex cells and hormones.
• Female Reproductive: produces sex cells and hormones.

Common Elements in the Body

• Oxygen (O)
• Carbon (C)
• Hydrogen (H)
• Nitrogen (N)

Plasma Membrane

• Structure: phospholipid bilayer with hydrophilic heads and hydrophobic tails.
• Function: regulates what enters and exits the cell.

Macromolecule and Polymer

• Macromolecule: large complex molecules made of smaller molecules.
• Monomer: small units that make up larger molecules.
• Polymers: chains of monomers linked together.
• Bonds: hold monomers together, examples include hydrogen bonds, ionic bonds, and covalent bonds.

REDOX Reactions

• Redox Reactions: involve the transfer of electrons from one chemical structure to another.

Membrane Transport

• Passive Transport: movement of molecules across the cell membrane without energy; examples include diffusion and osmosis.
• Active Transport: movement of molecules across the cell membrane using energy; examples include pumps.

Osmosis

• Osmosis: the movement of water across a selectively permeable membrane to equalize the concentration of solutes.

Diffusion

• Simple diffusion - the movement of molecules or ions from an area of high concentration to an area of low concentration.
• Facilitated diffusion - the movement of molecules or ions across a cell membrane from an area of high concentration to an area of low concentration facilitated by proteins that assist the passage of these ions or molecules.

Symport vs. Antiport

• Symport: transports two substances in the same direction.
• Antiport: transports two substances in opposite directions.

Vesicular Transport

• Exocytosis: releases substances from inside the cell by fusing vesicles with the cell membrane.
• Endocytosis: takes in substances from outside the cell by engulfing them with cell membrane.

Receptor-Mediated Transport

• Receptor-mediated transport is a type of endocytosis that is highly specific for the substance being taken into the cell.

Membrane Potential

• Difference in electrical charge across the cell membrane.

AP Sequence of Events

• Resting potential (-70mV)
• Depolarization (voltage across the membrane becomes positive)
• Repolarization (voltage across the membrane returns to its negative resting value)
• Hyperpolarization (voltage across the membrane temporarily becomes more negative than the resting value)

Nucleus

• DNA is located in the nucleus, in the form of chromatin or chromosomes.

DNA Structure

• Monomer: nucleotide
• Polymer: DNA (deoxyribonucleic acid)
• Bonds: phosphodiester bonds

Transcription of RNA

• Initiation: RNA polymerase binds to a promoter region on a DNA strand.
• Elongation: RNA polymerase reads the DNA template and creates a RNA molecule.
• Termination: RNA polymerase reaches a terminator sequence and stops creating the RNA molecule.

Translation

• Translation: mRNA codons are translated into amino acids by tRNA.
• tRNA aligns amino acids with their corresponding codons in mRNA.

Cell Division - Mitosis

• Interphase: DNA replication.
• Prophase: chromatin condenses into chromosomes, nuclear envelope breaks down, centrioles move to opposite poles.
• Metaphase: chromosomes align along the center of the cell, spindle fibers attach to centromeres.
• Anaphase: sister chromatids separate and are pulled to opposite poles.
• Telophase: nuclear envelope reforms around each set of chromosomes, chromosomes decondense, two separate nuclei form.
• Cytokinesis: cell cytoplasm divides into two daughter cells.

Cell Cycle

• Interphase: G1, S, & G2. Preparation for and replication prior to cell division.
• Mitosis: cell division of somatic cells.

Integument (skin)

• Epidermis (top layer): protects against water loss and substances/organisms; stratified squamous epithelium, provides a barrier.
• Dermis (deeper layer): contains blood, lymph vessels, nerves, hair follicles, and sweat glands; dense irregular connective tissue.
• Hypodermis (subcutaneous): fat and connective tissue, not part of the integument or skin.

Composition of Dermis

• Connective tissue—collagen, elastic fibers, blood vessels, nerves.
• Sweat glands, sebaceous glands, hair follicles, nail roots, and arrector pili.

Hair Follicle & Hair

• Keratinized cells growing from hair follicles.
• Structure and general functions.

Nervous System

• Brain, spinal cord, and nerves.

General Organization of Nervous System

• Sensory neurons (afferent): transmit signals from receptors to the CNS.
• Motor neurons (efferent): transmit signals from the CNS to effectors.

Neuron Structures

• Dendrites: receive signals from other neurons.
• Axons: transmit signals to other neurons.

Synaptic Transmission

• Neurotransmitters: chemical messengers.
• Synaptic vesicles: store neurotransmitters.

General Functions of Cerebrum

• Conscious thought and intellectual function.

Hypothalamus

• Regulates body temperature, controls autonomic functions (e.g., heart rate, blood pressure, respiration) and the endocrine system.

Osteoblast

• Builds bone.

Osteoclast

• Breaks down bone.

Osteoprogenitor Cells

• Stem cells for bone formation.

Muscle Tissue

• Skeletal: striated, voluntary.
• Smooth: involuntary, lines the walls of hollow organs.
• Cardiac: striated, involuntary, found in the heart.

Process of Muscle Contraction

• Nerve impulse (AP) begins.
• AP travels along muscle fiber membrane (sarcolemma)
• Excitation-contraction coupling. Ca2+ is released from sarcoplasmic reticulum.
• Cross bridge formation. Myosin heads attach to actin fibers.
• Powerstroke. Myosin heads pivot, pulling actin fibers.
• Detachment. ATP binds to myosin heads which detaches from actin.
• Relaxation. Nerve signal stops, Ca2+ levels decrease, tropomyosin returns to original position.

Test your knowledge on the various functions and components of cells in this quiz. Questions cover topics such as mitochondria, feedback mechanisms, and cellular organelles. Perfect for students studying biology.