Bio 181 Exam 1 MCC

Biological Organization

1. Biosphere 2. Ecosystem 3. Communities 4. Populations 5. Organisms 6. Organs and Organ Systems 7. Tissues 8. Cells 9. Organelles 10. Molecules

Darwin's groundbreaking observations

1. Individuals within a population vary their traits, many of which are heritable (passed to offspring). 2. A population produces far more offspring that can then survive to produce their own offspring. 3. Species are generally adapted to their environments

Properties of life

1. Order 2. Regulation 3. Energy Processing 4. Evolutionary Adaptation 5. Response to the Environment 6. Reproduction 7. Growth and Development

What is an ion? What is a cation and an anion?

A cation is a positively charged ion and an anion is a negatively charged ion. An ionic bond is an attraction between an anion and a cation

What is a compound?

A compound is a substance consisting of two or more elements in a fixed ratio. A compound has characteristics different from those of its elements

What is a covalent bond?

A covalent bond is the sharing of a pair of valence electrons by two atoms. In a covalent bond, the shared electrons count as part of each atom's valence shell

Eukaryotic organisms/cells

A eukaryotic cell has membrane-enclosed organelles, the largest of which is usually the nucleus

What is a hydrogen bond?

A hydrogen bond forms when a hydrogen atom covalently bonded to one electronegative atom is also attracted to another electronegative atom. In living cells, the electronegative partners are usually oxygen or nitrogen atoms

What is a lysosome?

A lysosome is a membranous sac of hydrolytic enzymes that can digest macromolecules.

What is a molecule?

A molecule consists of two or more atoms held together by covalent bonds

Molecular shape and function?

A molecule's shape is usually very important to its function. EX: endorphins and morphine

Natural Selection

A process in which individuals that have certain inherited traits tend to survive and reproduce at higher rates than other individuals because of those traits.

Prokaryotic organisms/cells

A prokaryotic cell is simpler and usually smaller, and does not contain a nucleus or other membrane-enclosed organelles

What is a single bond? What is a double bond?

A single covalent bond, or single bond, is the sharing of one pair of valence electrons. A double covalent bond, or double bond, is the sharing of two pairs of valence electrons

How can you estimate an elements atomic mass?

Atomic mass, the atom's total mass, can be approximated by the mass number

What is an essential element?

About 20-25% of the 92 elements are essential to life (essential elements). Carbon, hydrogen, oxygen, and nitrogen make up 96% of living matter

How do actin-myosin filaments help with cell movement?

Actin filaments, usually in association with myosin, are responsible for many types of cell movements. Myosin is the prototype of a molecular motor—a protein that converts chemical energy in the form of ATP to mechanical energy, thus generating force and movement. The most striking variety of such movement is muscle contraction, which has provided the model for understanding actin-myosin interactions and the motor activity of myosin molecules.

What characteristics are common between cells?

All living things use DNA as genetic material. Even viruses are able to use RNA, but their position as organisms is highly debated. The plasma membrane is at least a phospholipid bilayer with embedded proteins for stability, communication and import and export of nutrients. The cytoplasm is the liquid material of the cell that contains membrane-bound organelles in eukaryotes. Inside the cytoplasm and embedded certain organelles are ribosomes, which are responsible for protein synthesis.

What are the three types of subatomic particles and what are their charges?

Atoms are composed of subatomic particles § Relevant subatomic particles include § Neutrons (no electrical charge) § Protons (positive charge) § Electrons (negative charge) Neutrons and protons form the atomic nucleus § Electrons form a cloud around the nucleus § Neutron mass and proton mass are identical

How do valence electrons relate to chemical bonds?

Atoms with incomplete valence shells can share or transfer valence electrons with certain other atoms § These interactions usually result in atoms staying close together, held by attractions called chemical bonds

What is an atom?

An atom is the smallest unit of matter that still retains the properties of an element

What is an atoms electron shell?

An electron's state of energy is called its energy level, or electron shell

What is a element?

An element is a substance that cannot be broken down to other substances by chemical reactions

What is an elements atomic number? What is an elements mass number?

An element's atomic number is the number of protons in its nucleus. An element's mass number is the sum of protons plus neutrons in the nucleus

What is the extracellular matrix and how does it help cells?

Animal cells lack cell walls but are covered by an elaborate extracellularmatrix (ECM) • The ECM is made up of glycoproteins such as collagen, the most abundant animal protein. • ECM proteins bind to receptor proteins in the plasma membrane • ECM functions in cell support and adhesion.

What are weak chemical bonds?

Most of the strongest bonds in organisms are covalent bonds that form a cell's molecules. Weak chemical bonds are also indispensable. Many large biological molecules are held in their functional form by weak bonds. The reversibility of weak bonds can be an advantage

Which of these two organelles are found only in plants?

Both plant and animal cells have mitochondria, but only plants have chloroplasts

Bound ribosomes

Bound ribosomes are on the outside of the endoplasmic reticulum or the nuclear envelope. Bound ribosomes produce proteins that are transported out of the cell. This includes proteins that are required for a specific function, such as digestive enzymes. Bound ribosomes also produce polypeptide hormones. A few proteins produced by bound ribosomes are used in the cell membrane and on the outer surface of the cell. Surface receptors and cell signaling proteins are produced by bound ribosomes.

Reductionism

reducing a complex system into smaller parts. each level of the system shows correlation between structure and function. EX: study of molecular structure of DNA helps us to understand chemical basis of inheritance.

What is a chemical reaction? What is a reactant and a product?

Chemical reactions are the making and breaking of chemical bonds. The starting molecules of a chemical reaction are called reactants. The final molecules of a chemical reaction are called products

What are chloroplasts?

Chloroplasts contain the green pigment chlorophyll, as well as enzymes and other molecules that function in photosynthesis. Chloroplasts are found in leaves and other green organs of plants and in algae

What is an ionic bond?

Compounds formed by ionic bonds are called ionic compounds, or salts. Salts, such as sodium chloride (table salt), are often found in nature as crystals

What is a cristae? Whats is its purpose in the mitochondria?

Cristae present a large surface area for enzymes that synthesize ATP. The infoldings or inward projections of the inner membrane of the mitochondrion, which are studded with proteins and increase the surface area for chemical reactions to occur like cellular respiration.

Three Domains of Life

Domain Bacteria (prok.) Domain Archaea (prok.) Domain Eukarya (euka., plants, fungi, animals, protests)

What is a centrosome?

The organelle located near the nucleus in the cytoplasm that divides and migrates to opposite poles of the cell during mitosis, and is involved in the formation of mitotic spindle, assembly of microtubules, and regulation of cell cycle progression; the region pertaining to the organelle.

What is a polar covalent bond?

In a polar covalent bond, one atom is more electronegative, and the atoms do not share the electron equally

What does the word Eukaryotic mean broken down in greek?

Eukaryotic means true nucleus. Animal and plant cells both have a membrane enclosing the nucleus. Prokaryotes are bacteria. They don't have a membrane around their nucleus so they don't have a true membrane. Instead of having a nucleus, prokaryotes have a nucloid. Bacteria mutate a lot to adapt to their environment.

Free ribosomes

Free ribosomes produce proteins that are used by the cell. This includes proteins that are used for the metabolism of food. The free ribosomes produce enzymes involved in the metabolism of glucose.

If a cell had a high rate of protein synthesis, it must also have a high number of...?

If a cell had a high rate of protein synthesis, it must also have a high number of RIBOSOMES (digestive,muscle systems)

What is a non-polar covalent bond?

In a nonpolar covalent bond, the atoms share the electron equally

What is the endosymbiont theory? How does it relate to mitochondria?

Mitochondria and chloroplasts have similarities with bacteria • Enveloped by a double membrane • Contain free ribosomes and circular DNA molecules • Grow and reproduce somewhat independently in cells • These similarities led to the endosymbiont theory The endosymbiont theory suggests that an early ancestor of eukaryotes engulfed an oxygen-using nonphotosynthetic prokaryotic cell • The engulfed cell formed a relationship with the host cell, becoming an endosymbiont • The endosymbionts evolved into mitochondria • At least one of these cells may have then taken up a photosynthetic prokaryote, which evolved into a chloroplast

What is an isotope?

Isotopes are two atoms of an element that differ in number of neutrons. Radioactive isotopes decay spontaneously, giving off particles and energy

What are the three types of cytoskeleton proteins and what are their functions?

Microfilaments -Microfilaments are fine, thread-like protein fibers, 3-6 nm in diameter. They are composed predominantly of a contractile protein called actin, which is the most abundant cellular protein. Microfilaments' association with the protein myosin is responsible for muscle contraction. Microfilaments can also carry out cellular movements including gliding, contraction, and cytokinesis. Microtubules -Microtubules are cylindrical tubes, 20-25 nm in diameter. They are composed of subunits of the protein tubulin--these subunits are termed alpha and beta. Microtubules act as a scaffold to determine cell shape, and provide a set of "tracks" for cell organelles and vesicles to move on. Microtubules also form the spindle fibers for separating chromosomes during mitosis. When arranged in geometric patterns inside flagella and cilia, they are used for locomotion. Intermediate Filaments -Intermediate filaments are about 10 nm diameter and provide tensile strength for the cell.

What are mitochondria?

Mitochondria are the sites of cellular respiration, a metabolic process that uses oxygen to generate ATP

Emergent Property

New properties that arise with each step upward in the hierarchy of life, owing to the arrangement and interactions of parts as complexity increases.

What is matter and why is it important in organisms?

Organisms are composed of matter § Matter is anything that takes up space and has mass

What is phagocytosis (Lysosomes)?

Phagocytosis is the process many cells use to eat smaller organisms or food particles.

Describe the scientific process

The scientific process includes making observations, forming logical hypotheses, and testing them. The word SCIENCE is derived from Latin and means "to know." INQUIRY is the search for information and explanations of natural phenomena.

What are ribosomes responsible for in the cell?

Ribosomes are complexes made of ribosomal RNA (similar to DNA) and protein that carry out protein synthesis. Ribosomes carry out protein synthesis in two locations: 1. In the cytosol (free ribosomes) 2. On the outside of the endoplasmic reticulum or the nuclear envelope (bound ribosomes)

What is the rough endoplasmic reticulum?

Rough ER, whose surface is studded with ribosomes 1. Has bound ribosomes, which produce proteins to be secreted. (e.g. insulin). 2. Produces membranes for the cell. All secretory protein must be kept separate from proteins produced in the cytosol, so they are packaged into transport vesicles, which eventually make their way to the golgi apparatus.

What do phylogenetic trees illustrate?

Scientists use tree-like maps called phylogenetic trees to describe the evolutionary relationships between species.

What is the smooth endoplasmic reticulum?

Smooth ER, which lacks ribosomes. 1. Synthesizes lipids (e.g., hormones in testes or ovaries). 2. Detoxifies drugs and poisons (e.g., alcohol in the liver). 3. Stores calcium ions (e.g., in muscle cells to help trigger muscle contractions).

What function does the golgi apparatus carry out within the cell?

The Golgi apparatus consists of flattened membranous sacs called cisternae. Functions of the Golgi apparatus: 1. Modifies products of the endoplasmic reticulum The Golgi apparatus has STRUCTURAL DIRECTIONALITY: each membrane on the opposite side of the cisternae has a different thickness and molecular composition. Cis à -"on the same side" The cis face usually is located on the same side as the ER and receives incoming vesicles. Trans à -"on the opposite side" The trans side sends out vesicles that then travel to other destinations.

What is the cell wall? Which organisms have a cell wall?

The cell wall is an extracellular structure that distinguishes plant cells from animal cells. Prokaryotes, fungi, and some unicellular eukaryotes also have cell walls • The cell wall supports the plant cell, maintains its shape, and keeps the cell from bursting. Plant cell walls are made of cellulose fibers embedded in other polysaccharides and protein

What is a plasma membrane?

The cell's outer membrane made up of a two layers of phospholipids with embedded proteins. It separates the contents of the cell from its outside environment, and it regulates what enters and exits the cell.

What is the function of the cytoskeleton in the cell?

The cytoskeleton is a network of fibers extending throughout the cytoplasm. It organizes the cellʼs structures and activities, anchoring many organelles

What is the endoplasmic reticulum?

The endoplasmic reticulum (ER) accounts for more than half of the total membrane in many eukaryotic cells! The ER membrane is continuous with the nuclear envelope.

What is a structural formula?

The notation used to represent atoms and bonding is called a structural formula. For example, H—H

What is the function of the nuclear envelope?

The nuclear envelope separates the nucleus from the rest of the cytoplasm with a double membrane.

What is the function of a nucleus?

The nucleus contains most of the genes within a cell.

What do nuclear pore complexes do?

The nucleus is dotted with pore complexes that allow the movement of certain molecules in and out of the nucleus.

How are cells related to each other?

They are all related together because they make up each other. Cells are living organisms. A group of two or more cells makes up a tissue. A group of two or more tissues make an organ. All the organs in our body are then grouped into systems like: Digestive System, Resportiary System and so on.

What is a molecular formula?

This can be abbreviated further with a molecular formula. For example, H2

What is autophagy (Lysosomes)?

This helps them break down damaged organelles and other cellular waste for excretion.

What is a trace element?

Trace elements are those required by an organism in only minute quantities

What is a vacuole? What are the three different types?

Vacuoles are large storage compartments derived from the endoplasmic reticulum and the Golgi apparatus. FOOD VACUOLES can be formed by phagocytosis (like we saw earlier). CONTRACTILE VACUOLES exist in fresh water eukaryotes to pump out extra water. Plants usually contain a large CENTRAL VACUOLE to hold extra water. When these are empty, plants look like they are wilting!

What is a valence electron?

Valence electrons are those in the outermost shell, or valence shell § The chemical behavior of an atom is mostly determined by the valence electrons § Elements with a full valence shell are chemically inert (not reactive)

What do vesicles do?

Vesicles perform a variety of functions. They mostly store, transport or digest cellular products and cellular waste. Since they are separate from the cytosol of the cell they have a completely different internal environment than the cell.

What is the genetic material of a cell? How is it organized in the cell?

Within the nucleus, DNA is organized into units called chromosomes, which carry genetic information. Each chromosome contains one long strand of DNA wrapped around small proteins to help wind the DNA into a smaller size to allow it to fit into the nucleus.

How does surface area relate to efficiency cells?

cells have a greater surface area relative to volume. greater surface area is effective at moving material in and out

Hierarchal Classification

classifies species from the most inclusive (domain) to the most specific species. Levels: 1. Atoms 2. Molecules 3. Organelles 4. Cells 5. Tissues 6. Organs 7. Organ systems 8. Organisms 9. Populations 10. Communities 11. Ecosystems 12. Biosphere

contrast

difference in brightness between light and dark areas of an image

cells

lowest level of organization that can perform all activities required for life. single common ancestor, thats been divided over and over.

resolution

measure of clarity in an image, distinguished at two points

What is an organelle?

membrane-enclosed structures that act as compartments. Plant and animal cells have most of the same organelles

What is the function of the nuclear lamina?

network of proteins that act like a net to support the nucleus main structure

magnification

ratio of a image size to an objects actual size

What is a protest?

single cell eukaryotic organisms not classified in their own kingdom but in the domain eukarya

descent with modification

species showed evidence of this from a common ancestor. the concept demonstrates unity, but also diversity in the modification of branched species. it is the ACTUAL OCCURRENCE not process of natural selection

What do fossils tell us about the natural history of life on earth?

tells us about ancestor species that don't exist on earth anymore. we can analyze fossil records and find evidence of current species

What is the function of the endomembrane system? What are the components of the endomembrane system?

the endomembrane system regulates protein traffic and performs metabolic functions in the cell. This system includes the nuclear envelope, endoplasmic reticulum, golgi apparatus, Lysosomes, vacuoles, and the plasma membrane. All of these organelles are connected either by structure or with vesicles

Unity (Evolution)

the process of change that has transformed life on earth. Biological unity is similarities between organisms due to evolution from a common ancestor. organisms of a common ancestor. EX: wings/arms and their unity coming from evolution.

What is light microscopy?

this is how scientists study cells. light passed through specimen, then through glass lenses

What is electron microscopy?

uses a beam of electrons rather than light to visualize an image. EX: scanning microscopy and transmission microscopy

transmission microscopy

uses an electron beam to see the internal structure of a cell. specimens sliced thin, sent through and scatter though objects

scanning microscopy

uses electron beam to scan the surface of a sample. great for looking at the shape or surface of the sample

Three types of cell junctions

• At tight junctions, membranes of neighboring cells are pressed together, preventing leakage of extracellular fluid • Desmosomes (anchoring junctions) fasten cells together into strong sheets • Gap junctions (communicating junctions) provide cytoplasmic channels between adjacent cells