Bio Exam Semester 1

Protons

Protons

positively charged particles found in the nucleus

Electrons

Negatively charged particles found around the nucleus

Neutrons

the particles of the nucleus that have no charge

Isotopes

Atoms of the same element that have different numbers of neutrons

Ion

An atom or group of atoms that carries a positive or negative electric charge as a result of having lost or gained one or more electrons.

covalent bond

A chemical bond that involves sharing a pair of electrons between atoms in a molecule

ionic bond

Formed when one or more electrons are transferred from one atom to another

Where are protons located in an atom?

They are positively charged and are found Inside atomic nucleus's

Where are neutrons located in an atom?

They dont have a positive or negative charge and are located in the nucleus

Where are electrons located in an atom?

They're located around the nucleus

What makes an ion positive or negative?

If the atom has more electrons than protons, it is a negative ion, or ANION. If it has more protons than electrons, it is a positive ion

Describe the difference between a hydrophobic and hydrophilic molecule

Hydrophilic means water loving, hydrophobic means water fearing. Hydrophilic molecules get absorbed or dissolved in water while hydrophobic molecules get dissolved/absorbed in oil based substances.

Monomer

A simple compound whose molecules can join together to form polymers

Polymer

A long molecule consisting of many similar or identical monomers linked together.

Carbohydrates

the starches and sugars present in foods

Monosaccharides

glucose, fructose, galactose

Disaccharide

A double sugar, consisting of two monosaccharides joined by dehydration synthesis.

Polysaccharides

Carbohydrates that are made up of more than two monosaccharides

Suffix - ose

Tells that a substance is a sugar. ex: Ribose, glucose, fructose

Lipid

macromolecule made mostly from carbon and hydrogen atoms; includes fats, oils, and waxes

Phospholipids

A molecule that is a constituent of the inner bilayer of biological membranes, having a polar, hydrophilic head and a nonpolar, hydrophobic tail.

saturated fats

A fat that is solid at room temperature and found in animal fats, lards, and dairy products.

unsaturated fats

A fat that is liquid at room temperature and found in vegetable oils, nuts, and seeds.

Protein

macromolecule that contains carbon, hydrogen, oxygen, and nitrogen; needed by the body for growth and repair

amino acids

building blocks of proteins

nucleic acids

macromolecules containing hydrogen, oxygen, nitrogen, carbon, and phosphorus.

hydrolysis reaction

A chemical reaction that breaks apart a larger molecule by adding a molecule of water

dehydration synthesis reaction

A chemical reaction in which two molecules covalently bond to each other with the removal of a water molecule.

Monosaccharides are the monomers of ____

carbohydrates

Amino acids are the monomers of ____

proteins

Glycerol and fatty acids are the monomers of

lipids

Nucleotides are the monomers of

Dna/nuclaic acids

Describe the difference between mono, di, and polysaccharide

Monosaccharides are carbohydrates with one molecule. Disaccharides are composed of two monosaccharides linked together, and polysaccharides are composed of 3 or more monosaccharides linked together.

Enzymes

Catalysts for chemical reactions in living things

activation energy

Energy needed to get a reaction started

catalyst

substance that speeds up the rate of a chemical reaction

Substrate

reactant of an enzyme-catalyzed reaction

Reactant

A chemical substance that is present at the start of a chemical reaction

product

A substance produced in a chemical reaction

active site

The part of an enzyme or antibody where the chemical reaction occurs.

Inhibitors of enzymes

Can be competitive or non competitive and slow the rate of reaction

competitive inhibition

Inhibition of an enzyme's ability to catalyze a chemical reaction via a non-reactant molecule that competes with the substrate(s) for access to the active site.

non-competitive inhibitor

A substance that reduces the activity of an enzyme by binding to a location remote from the active site, changing its conformation so that it no longer binds to the substrate.

lock and key model

The model of the enzyme that shows the substrate fitting perfectly into the active site

induced fit model

Change in the shape of an enzyme's active site that enhances the fit between the active site and its substrate(s)

feedback inhibition

A method of metabolic control in which the end product of a metabolic pathway acts as an inhibitor of an enzyme within that pathway.

Whats the suffix for an enzyme?

-ase. example: lipase, amylase, maltase

Describe how an enzyme speeds up a reaction by acting as a biological catalyst and lowering the activation energy

Enzymes work by binding to reactant molecules and holding them in such a way that the chemical bond-breaking and bond-forming processes take place more readily.

Differentiate between competitive and non-competitive inhibition.

A competitive inhibitor structurally resembles the substrate for a given enzyme and competes with the substrate for binding at the active site of the enzyme. A noncompetitive inhibitor binds at a site distinct from the active site and can bind to either the free enzyme or the enzyme-substrate complex.

phospholipid bilayer

a two-layered arrangement of phosphate and lipid molecules that form a cell membrane, the hydrophobic lipid ends facing inward and the hydrophilic phosphate ends facing outward.

plasma membrane

A selectively-permeable phospholipid bilayer forming the boundary of the cells

fluid moasic model

model that describes the arrangement and movement of the molecules that make up a cell membrane

Aquaporins

A transport protein in the plasma membrane of a plant or animal cell that specifically facilitates the diffusion of water across the membrane

Diffusion

the process by which molecules move from an area of higher concentration to an area of lower concentration

Osmosis

diffusion of water across a selectively permeable membrane

Hydrophilic

water loving, polar

Hydrophobic

Water fearing, non polar

active transport

the movement of ions or molecules across a cell membrane into a region of higher concentration, assisted by enzymes and requiring energy.

Endocytosis

process by which a cell takes material into the cell by infolding of the cell membrane

Exocytosis

Process by which a cell releases large amounts of material

Tonicity

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

isotonic solution

A solution in which the concentration of solutes is equal to that of the cell which resides in the solution

Hypertonic solution

Solute concentration is greater than that inside the cell; cell loses water

hypotonic solution

Solute concentration is less than that inside the cell; cell gains water

selective permeability

A property of biological membranes that allows some substances to cross more easily than others.

What molecules are able to pass through the cell membrane?

Small, non-polar molecules like O2 and CO2

What molecules are not able to pass through the cell membrane?

Large, polar molecules like glucose or amino acids.

How do isotonic solutions impact the cell?

there will be no net flow of water into or out of the cell, and the cell's volume will remain stable

How does a hypertonic solution impact a cell?

The cell will shrivel and die by a process known as plasmolysis.

How does a hypotonic solution impact a cell?

The cell will swell and expand until it eventually burst through a process known as cytolysis

Prokaryote

simple celled organism lacking a nucleus

Eurkaryote

more complex cell, membrane bound organelles, has nucleus

Nucleus

A part of the cell containing DNA and RNA and responsible for growth and reproduction

Nucleolus

Found inside the nucleus and produces ribosomes

cell wall

strong, supporting layer around the cell membrane in plant, algae, and fungi cells

Cytoplasm

A jellylike fluid inside the cell in which the organelles are sustained

Mitochondria

Powerhouse of the cell, organelle that is the site of ATP (energy) production

Chloroplast

An organelle found in plant and algae cells where photosynthesis occurs

Rough ER

That portion of the endoplasmic reticulum studded with ribosomes.

Smooth ER

That portion of the endoplasmic reticulum that is free of ribosomes. also makes lipids

Golgi apparatus

A system of membranes that modifies and packages proteins for export by the cell

Vacuole

Cell organelle that stores materials such as water, salts, proteins, and carbohydrates

Lysosome

An organelle containing digestive enzymes

Peroxisomes

Contain oxidase enzymes that detoxify alcohol, hydrogen peroxide, and other harmful chemicals

Cytoskeleton

network of protein filaments within some cells that helps the cell maintain its shape and is involved in many forms of cell movement

Ribosomes

site of protein synthesis

What are the differences between plant and animal cells?

Animal cells each have a centrosome and lysosomes, whereas plant cells do not. Plant cells have a cell wall, chloroplasts and other specialized plastids, and a large central vacuole, whereas animal cells do not.

ATP

(adenosine triphosphate) main energy source that cells use for most of their work

ADP

(Adenosine Diphosphate) The compound that remains when a phosphate group is removed from ATP, releasing energy

celluar respiration

the process in cells in which oxygen is used to release stored energy by breaking down sugar molecules

Photosynthesis

Plants use the sun's energy to convert water and carbon dioxide into sugars

aerobic respiration

Respiration that requires oxygen

anaerobic respiration

Respiration that does not require oxygen

lactic acid fermentation

The conversion of pyruvate to lactate with no release of carbon dioxide.

alcoholic fermentation

the anaerobic process by which yeasts and other microorganisms break down sugars to form carbon dioxide and ethanol

What are the reactants and products of cellular respiration and photosynthesis

The reactants of photosynthesis are carbon dioxide and water, which are the products of cellular respiration. The reactants of cellular respiration are oxygen and sugar, which are the products of photosynthesis.

Identify when lactic acid fermentation would occur and the effects of its byproducts.

Inadequate oxygen supply in human muscle cells leads to anaerobic respiration. Thus, lactic acid fermentation takes place to produce energy molecules. Lactic acid is the byproduct of this process. Excessive buildup of lactic acid creates muscle discomfort called cramps.

Chromosome

A threadlike, gene-carrying structure found in the nucleus. Each chromosome consists of one very long DNA molecule and associated proteins.

sister chromatids

Replicated forms of a chromosome joined together by the centromere and eventually separated during mitosis or meiosis II.

Centromere

the region of the chromosome that holds the two sister chromatids together during mitosis