ZOOLONE Module 01-06 (Long Exam 1)

Unifying Themes in Biology, The Animal Cell, Membrane Transport, Cellular Respiration, Cell Cycle, Introduction to Genetics

Evolution

- process of change that has transformed life on Earth
- results in an organism’s adaptations to its environment

Order
Evolutionary adaptation
Regulation
Reproduction
Response to the environment
Growth and development
Energy Processing

7 Properties of Life

Organization, Information, Energy and matter, Interactions, & Evolution

5 Unifying Themes of Biology

Organization

Biosphere, Ecosystem, Communities, Population, Organism, Organs and Organ Systems, Tissues, Cells, Organelles, Molecules

Emergent properties

- result from the arrangement and interaction of parts within a system
- can characterize non-biological entities as well
- allows a system to be fully functional if everything falls to their perfect places

Reductionism

a theory that refers to:

the reduction of complex systems to simpler components that are more manageable to study

Systems Biology

analysis of the interactions among the parts of a biological system

Structure and Function

- organism’s basic unit of ___ = cell
- lowest level of organization that can perform activities required for life

Information: DNA

Genes encode info for building molecules & are units of inheritance

Genomics

the study of genes within and between species

Proteomics

the study of whole sets of proteins encoded by the genome (proteomes)

"High-throughput" technology

tools that can analyze many samples very rapidly

Bioinformatics

use of computational tools to store, organize, and analyze huge volume of data

Formation of interdisciplinary research teams

groups of diverse specialists

Energy (and matter)

- input of ___ from the sun and the transformation of ___ one form to another
- when used to perform work, some is lost to surroundings as heat
- usually enters as light, exits as heat

Interactions

- ___ between the components of the system ensure smooth integration of all parts
- ___ of organisms and environment affect each other

Positive Feedback

type of feedback wherein a reaction causes another reaction
(ex. contractions during childbirth)

Negative Feedback

type of feedback wherein the system brings the organism to its original state & maintain homeostasis
(ex. change in body temp)

Taxonomy

branch of biology that names & classifies species into groups of increasing breadth

Levels of Classification

Domain, Kingdom, Phylum, Class, Order, Family, Genus, Species

Binomial Nomenclature

Genus species

3 Domains

Bacteria, Archaea, Eukarya

Kingdoms under Domain Eukarya

Animalia, Plantae, Fungi

Darwin's observation

- individuals in a population vary in their traits, many of which are heritable
- more offspring are produced than survive, and competition is inevitable
- species generally suit their environment

Darwin's conclusion (Natural Selection)

- individuals are best suited to their environment are more likely to survive and reproduce
- over time, more individuals in a population will have advantageous traits

Tree of Life

“unity in diversity” arises from “descent with modification”

Subdisciplines of Zoology

Anatomy, Cytology, Ecology, Embryology, Genetics, Histology, Molecular Biology, Parasitology, Physiology, Systematics

Specialization in Zoology

Entomology, Helminthology, Herpetology, Ichthyology, Mammalogy, Ornithology, Protozoology

Cells

- fundamental unit of life
- can be seen using microscope

Light Microscope

- a type of microscope with visible light passing through a specimen and then through the glass lenses
- can magnify up to about 1000x the size of the actual specimen

Electron Microscope

- a type of microscope used to study subcellular structures

Scanning Electron Microscope (SEM)

type of electron microscope that focuses the electron beams on the surface of the specimen

Transmission Electron Microscope (TEM)

type of electron microscope that is used to study internal structures of cells

Cell Fractionation

- process that takes cells apart and separates the major organelles from another
- enables scientists to determine the function of each organelles

Centrifugation

the process of separating organelles of different densities inside a test tube by the use of a centrifuge

Prokaryotic Cell

type of cell:

NO true nucleus
LACKS nuclear membrane
genetic material in nucleic region
NO membrane-bound organelles
cytoplasm is bound by plasma membrane

Eukaryotic Cell

type of cell:

with true nucleus
bounded by nuclear envelope
genetic material within nucleus
contains cytoplasm with cytosol and membrane-bound organelles

Basic Features of All Cells

Plasma Membrane, Cytosol, Chromosomes, Ribosomes

Plasma Membrane

organelle:

- selective barrier that allows a sufficient passage of oxygen, nutrients, and waste to service the volume of every cell
- bi-layer of phospholipids

Nucleus

organelle:
- information central
- contains most of the cell’s genes
- most conspicuous organelle

Nuclear envelope

organelle:

- encloses nucleus
- separates nucleus from cytoplasm

nuclear membrane

part of nucleus:

- a double membrane
- each membrane consists of a lipid bilayer

nucleolus

- located within nucleus
- may vary in numbers
- the site of ribosomal RNA (rRNA) synthesis

Nuclear pores

part of nucleus that regulates entry and exit of molecules

nuclear lamina

- lines nuclear envelope
- maintains shape of nucleus
- composed of proteins

Ribosomes

organelle:

- protein factories
- complexes made of ribosomal RNA & protein
- carries protein synthesis in cytosol and outside the ER

Endomembrane System

system in a cell that:

- regulates protein traffic & performs metabolic functions
- made up of:
- nuclear envelope
- endoplasmic reticulum
- golgi apparatus
- lysosomes
- vacuoles
- plasma membrane

Endoplasmic Reticulum (ER)

organelle:
- biosynthetic factory
- accounts for more than half of the total membrane in many eukaryotic cells
- continuous with the nuclear envelope

Smooth ER

type of ER that:

- lacks ribosomes
- synthesizes lipids
- metabolizes carbs
- detoxifies drugs & poisons
- stores calcium ions

Rough ER

type of ER that:

- is studded with ribosomes (secrete glycoproteins)
- distributes transport vesicles
- is the membrane factory for the cell

Golgi Apparatus

organelle:

- shipping and receiving center
- made up of flattened membranous sacs (Cisternae)
- functions:
- modifies products of the ER
- manufactures certain macromolecules
- sorts and packages materials into transport vesicles

Lysosome

organelle:

- digestive compartments
- membranous sac of hydrolytic enzymes that can digest macromolecules
- enzymes work best in its acidic environment
- hydrolytic enzymes and ___'s membranes are made by the RER and transferred by GA for further processing

Phagocytosis

type of endocytosis:

- "cellular eating"
- process in which lysosomes digest food from the food vacuole
- cell engulfs a particle in the vacuole
- vacuole fuses with a lysosome to digest the particle

Autophagy

process in which lysosomes break down damaged organelles

Vacuoles

organelle:

- digestive maintenance compartments
- large vesicles derived from ER & GA

Food Vacuole

type of vacuole:

- formed by phagocytosis
- from plasma membrane

Contractile Vacuole

type of vacuole:

- found in freshwater protists
- pump excess water out of cell

Central Vacuole

type of vacuole:

- found in mature plant cells
- NONE in animal cells
- hold organic compounds and water

Mitochondria and Chloroplast

Pair of organelles that:

- both change energy from one form to another
- have similarities with bacteria:
- double membranes, contain free ribosomes

Mitochondria

organelle:

- sites of cellular respiration
- metabolic process that uses oxygen to generate ATP
- chemical energy conversion
- smooth outer membrane & inner membrane folded into Cristae
- inner membrane creates 2 compartments: intermembrane space & mitochondrial matrix

Chloroplast

organelle:

- found in plants and algae
- sites of photosynthesis

Endosymbiont Theory

a theory that basically shows ancestry of mitochondria and chloroplast

ancestor eukaryotic cell > engulfed a prokaryotic cell > engulfed cell > endosymbiont > mitochondria > chloroplast

Peroxisomes

organelle:

- specialized metabolic compartments
- produce hydrogen peroxide and convert to water
- unknown relationship with other organelles

Cytoskeleton

organelle:

- network of fibers that organizes structures & activities in the cell
- help support the cell and maintain its shape
- 3 types: microtubules, microfilaments, intermediate filaments:

microtubules

type of cytoskeleton:

- thickest of the 3 cytoskeleton compartments
- hollow tubes
- functions: cell motility, chromosome movement, & organelle movement
- centrosome has a pair of centrioles, each with 9 triplets of ___ arranged in a ring
- seen in cilia & flagella

Dynein

motor protein that drives the bending movements of a cilium or flagellum

Microfilaments

type of cytoskeleton:

- actin filaments
- thinnest
- functions:
- changes in cell shape
- muscle contraction
- cell motility
- division of animal cells

Intermediate filaments

type of cytoskeleton:

- fibers w diameters in a middle range
- fibrous proteins coiled into cables
- function:
- anchorage of nucleus and some organelles
- formation of nuclear lamina

Extracellular Matrix (ECM)

- alternative to cell wall for animal cells
- made of glycoproteins (collagen, proteoglycans, & fibronectin)
- bind to receptor proteins (integrins) in plasma membrane

Tight Junctions

type of cell junction:

- member of neighboring cells pressed together
- prevents leakage of extracellular fluid
- “glue”

Desmosomes

type of cell junction:

- anchoring junctions
- fasten cells together into strong sheets
- “sewn together”

Gap junctions

type of cell junction:

- "communicating junctions"
- provide cytoplasmic channels between adjacent cells

Phospholipids

- most abundant lipid in the plasma membrane
- amphipathic (hydrophilic head & hydrophobic tails)
- exist as a stable boundary between 2 aqueous compartments

Fluid Mosaic Model

a model:

- another term for plasma membrane
- fluid structure w/ various proteins embedded in it (NOT randomly distributed)
- constantly move with the flow yet not displaced

Fluidity of the Membrane

- phospholipids can move within the bilayer
- mostly drift laterally
- rare for it to flip-flop transversely across the membrane

Peripheral protein

type of membrane protein that is bound to the surface of the membrane

Integral protein

type of membrane protein that penetrates hydrophobic core

Transmembrane protein

type of integral protein that spans the membrane

6 Major Functions of Membrane Proteins

Transport
Enzymatic activity
Signal transduction
Cell-cell recognition
Intercellular Joining
Attachment to cytoskeleton & ECM

Formation of Proteins

steps:

1. Formed in ER
2. carried to GA for segregation and packing into a trans phase vesicle
3. vesicle will go to plasma membrane to release proteins

Transport Proteins

type of protein that allows passage of hydrophilic substance across membrane

Channel proteins

type of transport protein that is a hydrophilic channel that certain molecules can use as a tunnel

Aquaporin

type of channel protein that facilitates the passage of water

Carrier Protein

type of transport protein that bind molecules & change shape to shuttle them across membrane

Diffusion

type of membrane transport:

- movement of solutes from high to low concentration
- WITHOUT any energy investment
- tendency for molecules to spread out evenly into the available space
- follow concentration gradient
- reach equilibrium

Osmosis

type of diffusion:

- diffusion of water across selectively permeable membrane
- low to high solute concentration
- until both sides are equal

Tonicity

ability of surrounding solution to cause a cell to lose or gain water

Isotonic

type of solution wherein:

- the solute concentration is the same as inside the cell
- NO net movement

Hypertonic

type of solution wherein:

- solute concentration is greater outside the cell
- cell lose water
- becomes shriveled

Hypotonic

type of solution wherein:

- solute concentration is less than the inside of cell
- cell gains water
- may swell or burst

Osmoregulation

- control of solute concentrations and water balance
- needed for organisms that have problems with hypertonic or hypotonic environments
- present in freshwater & saltwater fish

Facilitated Diffusion

type of membrane transport:

- uses transport proteins to speed up passive movement

Ion channel

type of transport protein:

- facilitates diffusion of ions
- some are known as gated channels
- open and close in response to a stimulus

Active Transport

type of transport:

- AGAINST concentration gradient
- requires energy (ATP)
- allows cell to maintain concentration gradients that differ than their surroundings
- uses specific proteins

Membrane Potential

- voltage difference across a membrane
- created by differences in the distribution of positive and negative ions across a membrane

Electrochemical Gradient

- 2 combined forces: chemical & electrical forces
- drive the diffusion of ions across a membrane

Electrogenic Pump

pump wherein:

- transport protein that generates voltage across the membrane
- help store energy that can be used for cellular work

Sodium-Potassium pump

major electrogenic pump for animal cells

Proton Pump

major electrogenic pump for plants, fungi, and bacteria

Cotransport

type of transport:

- coupled transport by a membrane protein
- 2 different transports at once
- when active transport of a solute indirectly drives transport of other substances