bio bs

What are the 4 elements that make up 96% of all living matter?

carbon- oxygen- hydrogen- and nitrogen

What are subatomic particles?

a particle smaller than an atom in size

neutron

no charge - mass of 1 - located in the nucleus

proton

charge of +1 - mass of 1 - located in the nucleus

electron

charge of -1 - no mass - located outside of the nucleus

Determine the number of protons, electrons, and neutrons an element has if given the element’s atomic mass and atomic number.

you subtract the atomic number from the mass number in order to find the number of protons. if it is neutral, the number of electrons will be equal to the number of protons.

What is an isotope? How are isotopes used?

Isotopes are members of a family of an element that all have the same number of protons but different numbers of neutrons. For example, carbon 12, carbon 13, and carbon 14 are isotopes of carbon.

Explain the formation of compounds. Which subatomic particle plays a role in forming chemical \n bonds? What determines the reactivity of an element?

Electrons are the subatomic particles that play a role in forming chemical bonds. --The number of electrons in the outer most shell of an atom determine its reactivity.

Contrast atomic number/mass number

\--The atomic number is the number of protons in each atom of a particular atom. \n --The mass number is the sum of the number of protons and neutrons in an atom's nucleus.

contrast element/atom

\--An atom is the smallest unit of matter that retains the properties of an element. \n --An element is a substance that cannot be broken down to other substances by chemical means.

contrast compound/molecule

\--A compound is a substance containing two or more elements in a fixed ratio. \n --A molecule is two or more atoms held together by covalent bonds.

Distinguish between ionic, covalent, and hydrogen bonds. \n

* In a covalent bond, two atoms share one or more electrons.
* A hydrogen bond is a relatively weak bond between two oppositely partially charged sides of two or more molecules.
* In an ionic bond, an atom gives away one or more electrons to another atom.

Define a chemical reaction and explain how it changes the composition of matter.

chemical bonds in the reactants are broken and the elements in the reactants are rearranged, forming new chemical bonds and forming products with a different composition than the reactants.

Contrast polar and nonpolar covalent bonds.

Polar covalent bonds result when electrons are unequally shared between atoms, while nonpolar covalent bonds result when electrons are more equally shared between atoms

What kind of bond joins H and O to form water?

hydrogen bond

What kind of bonds causes water molecules to be \n attracted to one another?

hydrogen bond - cohesion

describe the life-supporting properties of water

water's role as a solvent helps cells transport and use substances like oxygen or nutrients

pH is the measurement of what?

a measure of how acidic/basic something is

Explain the pH scale.

The scale has values ranging from zero (the most acidic) to 14 (the most basic)

Compare and contrast acids and bases.

The pH of acids are values less than 7 and the pH of bases are greater than 7. Acids have a sour taste, and bases have a bitter taste.

What is a buffer?

the pH range where a buffer can effectively neutralize added acids and bases whilst maintaining a steady pH

Why is carbon so important for life?

carbon's ability to readily form bonds with other atoms, giving flexibility to the form and function that biomolecules can take, such as DNA and RNA, which are essential for the defining characteristics of life: growth and replication.

What is an organic compound?

is any chemical compound that contain carbon-hydrogen or carbon-carbon bonds

What is the importance of functional groups to molecules?

they are the portion of a molecule that is capable of characteristic reactions. They, therefore, determine the properties and chemistry of many organic compounds

How does a cell make a variety of large molecules from a small set of molecules?

The chains that cells make most of their large molecules by joining smaller molecules into chains called polymers

Explain the reactions of dehydration

*a process in which reactants lose one oxygen atom and two hydrogen atoms in the form of water molecules or molecules*.

Explain the reactions of hydrolysis. \n

a larger molecule forms two (or more) smaller molecules and water is consumed as a reactant

Define monosaccharides, disaccharides, and polysaccharides. Provide examples and explain their \n functions.

A monosaccharide is a single sugar molecule. This includes glucose, fructose, and galactose. Disaccharides are double sugars, such as sucrose (table sugar). Polysaccharides are long chains, such as plant and animal starches.

What are the monomers of carbohydrates?

glucose, fructose, and galactose

What are triglycerides, phospholipids, and steroids? Explain their functions.

Triglycerides: Function as a long-term energy source in animals (fats) and plants (oils) Phospholipids: Structural component of cell membranes. Steroids: Act as hormones in plants and animals, and is a structural component of animal cell membranes (cholesterol)

What are lipids?

Lipids are fatty, waxy, or oily compounds that are soluble in organic solvents and insoluble in polar solvents such as water.

What is the difference between saturated and unsaturated fats?

Saturated fatty acids lack double bonds between the individual carbon atoms, while in unsaturated fatty acids there is at least one double bond in the fatty acid chain

Explain how trans fats are formed in food

through a manufacturing process that adds hydrogen to vegetable oil, which converts the liquid into a solid fat at room temperature. This process is called hydrogenation

What are the monomers of proteins? How are the monomers joined together?

In a protein, amino acid monomers are held together by covalent peptide bonds between the amino group of one monomer and the carboxylic acid group of the adjacent monomer.

Describe each level of protein folding (1o, 2o, 3o, 4o)

The four levels of protein structure are primary, secondary, tertiary, and quaternary. The significance of the unique sequence, or order, of amino acids, known as the protein's primary structure, is that it dictates the 3-D conformation the folded protein will have. This conformation, in turn, will determine the function of the protein

What does it mean to denature a protein?

A protein becomes denatured when its normal shape gets deformed because some of the hydrogen bonds are broken.

Describe a nucleotide.

A nucleotide is a monomer that serves as the building blocks for deoxyribonucleic acid (DNA) or ribonucleic acid (RNA). Examples of nucleotides are ribonucleotides or deoxyribonucleotides.

Describe the process of gene expression.

the process by which the information encoded in a gene is turned into a function.

What is the purpose of a microscope?

used to observe small objects, even cells. The image of an object is magnified through at least one lens in the microscope

What is the cell theory?

a general statement in biology that all living things consist of cells each of which has come from a previously existing cell.

Explain why and how cell size is limited (surface area to volume ratio).

With larger cells, there is also less plasma membrane available to transport substances in and out of the cell since the surface area is reduced. This is why the surface area to volume ratio of cells limits cell size. The cell membrane is responsible for the transport of substances into and out of the cell.

Describe the structure and functions of plasma membranes.

The cell membrane consists of a lipid bilayer that is semipermeable. The cell membrane regulates the transport of materials entering and exiting the cell

What are the main differences between eukaryotic and prokaryotic cells

Prokaryotes are always unicellular, while eukaryotes are often multi-celled organisms.

examples of eukaryotic and prokaryotic organisms.

Examples of prokaryotes are bacteria and archaea. Examples of eukaryotes are protists, fungi, plants, and animals

Why is compartmentalization important to eukaryotic cells?

This compartmentalization vastly improves the efficiency of many cellular functions and prevents potentially dangerous molecules from roaming freely within the cell.

Compare the structures of plant and animal cells.

Plant cells have a cell wall in addition to a cell membrane, whereas animal cells have only a cell membrane.

Describe the basic structure of a prokaryotic cell.

All prokaryotic cells are encased by a cell wall. Many also have a capsule or slime layer made of polysaccharide. Prokaryotes often have appendages (protrusions) on their surface. - looks like a tampon

Describe the structure and function of the following cell parts: Nucleus, Ribosomes, Endomembrane

* The nucleus (plural, nuclei) houses the cell's genetic material, or DNA, and is also the site of synthesis for ribosomes, the cellular machines that assemble proteins.


* The endomembrane system includes the nuclear envelope, lysosomes, vesicles, the ER, and Golgi apparatus, as well as the plasma membrane. These cellular components work together to modify, package, tag, and transport proteins and lipids that form the membranes.
* A ribosome is an intercellular structure made of both RNA and protein, and it is the site of protein synthesis in the cell. The ribosome reads the messenger RNA (mRNA) sequence and translates that genetic code into a specified string of amino acids, which grow into long chains that fold to form proteins.

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Compare the structures and functions of chloroplasts and mitochondria.

Mitochondria are the "powerhouses" of the cell, breaking down fuel molecules and capturing energy in cellular respiration. Chloroplasts are found in plants and algae. They're responsible for capturing light energy to make sugars in photosynthesis.

What is the endosymbiont theory and what does it say about mitochondria and chloroplasts?

The endosymbiotic theory states that some of the organelles in eukaryotic cells were once prokaryotic microbes. Mitochondria and chloroplasts are the same size as prokaryotic cells and divide by binary fission. Mitochondria and chloroplasts have their own DNA which is circular, not linear.

Describe the cytoskeleton.

The cytoskeleton is a structure that helps cells maintain their shape and internal organization, and it also provides mechanical support that enables cells to carry out essential functions like division and movement. There is no single cytoskeletal component.

Compare the structures and functions of microfilaments, intermediate \n filaments, and microtubules.

Microfilaments thicken the cortex around the inner edge of a cell; like rubber bands, they resist tension. Microtubules are found in the interior of the cell where they maintain cell shape by resisting compressive forces. Intermediate filaments are found throughout the cell and hold organelles in place

Compare the structure and function of cilia and flagella.

Cilia has slender, microscopic, short hair like structure whereas flagella have long hair like filamentous cytoplasmic complex structure. Both are the most common organelles and have locomotive structures. They are found in unicellular organisms.

Describe the extracellular matrix of animal cells.

Most animal cells release materials into the extracellular space, creating a complex meshwork of proteins and carbohydrates called the extracellular matrix (ECM). A major component of the extracellular matrix is the protein collagen.

Compare the structures and functions of tight junctions, anchoring junctions, and gap junctions.

Unlike the gap junctions, tight junctions are found only in epithelial cells. Gap junctions are widespread in distribution. Tight junctions make barriers and prevent or reduce transport of substances in the extracellular space between cells while gap junctions make passages which allow passing molecules between cells.

What is the importance of a cell wall for plant cells?

It provides a structural framework to support plant growth and acts as the first line of defense when the plant encounters pathogens.

Do animal cells have cell walls?

no

Describe the four functional categories of organelles in eukaryotic cells.

Lysosomes - breaks down large molecules no longer needed by the cell and transports them to sites of disposal. Golgi Apparatus - modifies and sorts proteins. Nucleolus - site of ribosome manufacture. Vesicles/vacuoules - can store or transport different matter within a cell.