Powerpoint for First Exam Flashcards
How do unity and diversity go together?
All organisms–whether small or large–share a common chemical language for genetic material (DNA). Unity is as to descent, as diversity is as to modification.
How is this the Golden Age of biology?
Genetic engineering has caused a big breakthrough in biology, which is part of society as never before.
How are scale and scope two factors of life?
Life is structured on a size scale, ranging from molecular to global. Biology’s scope stretches across enormous diversity of life on Earth.
What’s the difference between prokaryotic and eukaryotic cells?
Prokaryotic cells do not contain nuclei, whereas eukaryotic cells do.
How many species exist and how are they ordered?
There are 1.9 million different species identified in the world. There are four kingdoms included in eukarya: protista (single-celled that do not fit with the other kingdoms), plantae (produce own sugars and other foods by photosynthesis), fungi (mostly decomposers, obtaining food by digesting dead organisms and organic wastes), and animalia (obtain food by ingesting and digesting other organisms).
How is evolution the unifying theme of all biology?
Newer species, as Darwin explained, descend from earlier species and change over time to adapt to new environments. Each species is one twig of a branching tree of life extending back in time through ancestral species.
What role did Charles Darwin play?
He published a book called The Origin of Species that developed two points: descent with modification and natural selection. He made two observations: overproduction and struggle for existence, and individual variation.
What is natural selection?
The process whereby organisms better adapted to their environment tend to survive and produce more offspring.
How does science work? What is the scientific method?
Science is a way of knowing. The scientific method includes observation, hypothesis, experimentation, and conclusion.
What are life-supporting properties of water?
Cohesive: the attraction between molecules of the same kind. This cohesion is much stronger for water than for most other liquids.
Temperature-modifying: water stores a huge amount of heat from the sun during warm periods and gives off heat to warm the air during cold conditions. Water also helps to moderate temperature by evaporative cooling, such as sweating. When a substance evaporates (the molecules with the greatest energy evaporates), the surface of the liquid remaining behind cools down.
Floating ice: when water molecules get cold enough, they move apart, forming ice. Floating ice is a consequence of hydrogen bonding. Molecules last longer.
Universal solvent: a liquid consisting of a homogeneous mixture of two or more substances. Sugar and salt can be both dissolved in water.
Solute: a substance that is dissolved in a liquid to form a solution. Water can dissolve many solutes that are necessary for life.
Solution: the dissolving agent in a solution. When water is the solvent, the solution is called the aqueous solution.
What are organic molecules? Inorganic?
Organic molecules are chemical compound containing the element carbon and usually synthesized (combined into a single entity) by cells. Inorganic compound do not contain hydrocarbon (which contain only carbon and hydrogen atoms) groups.
Why is carbon such a versatile atom?
Carbon is versatile because it can form single, double, or triple bonds. It can also form chains, branched chains, and rings when connected to other carbon atoms.
They contain 4 electrons in an outer shell that contains 8.
What are hydrolysis and dehydration synthesis?
Hydrolysis is the chemical breakdown of a compound due to reaction with water (water destroys). Dehydration synthesis is defined as a chemical reaction that involves the loss of a water molecule from the reacting molecule (remove water).
What are the types of carbohydrates? What do they do?
Monosaccharides: simple sugars that cannot be broken down into smaller sugars. The main fuel molecules for cellular work; for example, your cells break down glucose molecules and extract their stored energy, giving off “carbon dioxide.” Examples of monosaccharides are glucose (sports drinks) and fructose (honey).
Dissacharides: double sugars that are constructed by two monosaccharides. Most common example is table sugar, which consists of a glucose monomer linked to a fructose monomer. Dissacharides provide energy and help with digestion.
Polysaccharides: complex carbohydrates are long chains of sugars. A familiar example is starch. They usually perform one of two functions: energy storage (starch or glycogen) or structural support (cellulose).
What are the types of lipids? What do they do?
Fats: consists of a glycerol molecule joined with three fatty acid molecules via dehydration reactions; resulting fat is called a triglyceride. They perform essential function in the human body, such as energy storage, cushioning, and insulation (protection).
Phospholipids: molecules that are constituents of the inner bilayer of biological membranes, having a hydrophilic head (water-loving) and a hydrophobic tail (water-fearing). They are essential for the cell to have a defined volume and internal structures.
Steroids: Types of lipids (but not fats). Examples are cholesterol, testosterone, and estrogen. Cholesterol, which is your body’s “base steroid”, is important to cell membranes, and is the site in which the body produces other steroids such as sex hormones. Synthetic anabolic steroids, however, are dangerous.
What are the types of proteins? What do they do?
Proteins are macromolecules, which are constructed from a common set of 20 kinds of amino acids. Cells link amino acid monomers together by dehydration synthesis; the bond between amino acids is called a peptide bond. A long chain of amino acids is called a polypeptide.
Proteins do most of the work in cells and are required for the structure, function, and regulation of the body’s tissues and organs.
What are the types of nucleic acids? What do they do?
DNA (DeoxyriboNucleic Acid) and RNA (RiboNucleic Acid) are two types of nucleic acids. They are information storage molecules and give directions for building proteins (such as hormones, enzymes, etc.).
What are the building blocks of life?
Cells are the building blocks of life. They must be tiny so that materials can move in/out very quickly. Our body has more than 100 trillion cells.
What are cell membranes made of?
Cell membranes are composed of phospholipids, a special kind of lipid that actually does like water.
What is selective permeability?
It means that the cell membrane has some control over what can pass through it, so that only certain molecules either enter or leave the cell. Only small (size) and neutral (charge) molecules can pass through.
What is the role of the nucleus in the cell?
The nucleus is the manager of the cell. Within it is the majority of the cell’s genetic material (which are made up of proteins and DNA molecules to form chromosomes). Genes in the nucleus store information necessary to produce proteins.
What is the role of the ribosomes in the cell?
Ribosomes begin their work in the cytoplasm. Some make proteins that remain within the fluid of the cell, while others that are attached to the outside of the nucleus (the endoplasmic reticulum) make proteins that are incorporated into membranes or are secreted by the cell.
They are responsible for protein synthesis, and converts instructions found in mRNA into the chains of amino acids that make up proteins.
What is the role of the endoplasmic reticulum (ER)?
It produces an enormous variety of molecules. They also transport synthesized proteins in vesicles to the Golgi apparatus. There are two components that make up the ER: rough ER and smooth ER.
How are rough ER and smooth ER different?
Rough ER have bumps and stud the outside of its membrane, while smooth ER lacks the ribosomes that populate the surface of the rough ER.
Rough ER make more membrane by having phospholipids inserted into the ER membrane. Ribosomes attached to the rough ER produce proteins that will be inserted into the growing membrane, transported to other organelles, and eventually exported. Smooth ER produces lipids, including steroids, and also has enzymes that break down toxins, drugs, and other toxic byproducts.
What is the role of the Golgi Apparatus in the cell?
It receives, refines, stores, and distributes chemical products of the cell. Products made in the ER reach the Golgi apparatus in transport vesicles.
One side of G.A. serves as receiving dock for vesicles from ER –> proteins are usually modified by enzymes (ex: phosphate groups sorted into different batches for different destinations).
Other side serves as shipping dock for finished products –> carried out in transport vesicles to other organelles or to plasma membrane –> vesicles attached to plasma membrane transfer proteins to it or release them to outside of the cell
What is the role of lysosomes in the cell?
Lysosomes, a membrane-enclosed sac, are only found in animal cells (not plant cells). They develop from vesicles that detach from the Golgi. They act in digestion: enzymes within a lysosome can break down large molecules such as proteins, polysaccharides, fats, and nucleic acids. Lysosomes also help destroy harmful bacteria. They also break down molecules of damaged organelles, engulfing and digesting them and recycling them to make the molecules available for the formation of new organelles.
