Biology 105-115 Test 1

Electronegativity

a measure of the tendency of an atom to attract a bonding pair of electron

Homology

refers to any similarity in a biological structure or composition though not necessarily function.

Intermediates

steps in between the reactants and products

nonpolar covalent bond

occurs when two atoms share a pair of electrons with each other

similar electronegativities, electrons shared equally

polar covalent bond

when atoms with different electronegativities share electrons in a covalent bond

slightly negative, and slightly positive

ions

atoms that gains or loses elections

cation

atom that loses an electron and becomes positive

anion

atom that gains an electron and becomes negative

what takes up 75% of the volume of a cell?

water

hydrophillic

water-loving

hydrophobic

water-hating

electrolytes

true or false:

molecules that are nonpolar do not like to interact with water

true, they are HYDROPHOBIC

true or false: water is not a sticky substance

false, water loves itself and does not want to be seperated

cohesion

sticks to itself

adhesion

sticks to a surface

capillary action

allows water molecules to pull other molecules behind them

ex) water moving through the roots of a tree to reach the leaves

true or false: Substances that bind to hydrogen protons and remove them are called bases

true, bases are hydrogen acceptors

true or false: Substances that release hydrogen protons (H+) into an aqueous solution are called acids

true, acids are hydrogen donors

homeostasis

stability within a unit

What substances ( a combination of a weak acid and a weak base) made by organisms and cells allow them to keep the pH of solutions inside of them neutral?

buffers

Organic molecules

molecules that have carbon in their make up

Biochemical

any molecule built by a living cell

Carbon can bond with up to ____ other atoms

four, it needs four valence electrons to reach stability

functional groups

a specific group of atoms within a molecule that is responsible for a characteristic of that molecule

modular

made out of component parts

ex) modular homes are built in parts, and put together in the end

macromolecular structures

large molecular composites built out of a subunit building blocks

supramolecular structures

higher-order assemblies constructed from multiple molecules and macromolecules interacting together through noncovalent bonds

metabolism

all of the chemical reactions that take place inside of a living cell

polymers

long chains of monomer subunits linked covalently

pentose

5 carbon sugar

hexose

six carbon suagr

glycosidic linkages

links monosaccharides together

oligosaccharides

dozens of monosaccharides linked together

starch

long chains of glucose in PLANTS

glycogen

long chains of glucose in animals

chitin

long chains of glucose in insect exoskeleton

peptidoglycans

Long strands of sugars that are crosslinked together by proteins

true or false: suagrs do not contain many high-energy C-H bonds

false

“monomers” of lipids are…

fatty acids tails and glycerol

true or false: if the fatty acids contain double bonded carbons, the chain is saturated

true

Triglycerides

type of fat containing a 3-carbon glycerol backbone

Steroids

small lipids built around a 4-ringed carbon skeleton

ex) testosterone and estrogen

hydrophobic fatty acid tails face…

each other

hydrophilic phosphate heads face…

outwards

micelles

lipids with short tails

bilayers

lipids with long tails

N-Terminus of a protein is..

the free NH³ group

C-Terminus of a protein is…

the free carboxyl group (COO-)

R-Group of a protein is..

a side chain specific to each amino acid that confers particular chemical properties to that amino acid

Primary structure

simply describes the linear sequence of specific amino acids found in a polypeptide chain

Secondary structure

three-dimensional shape of specific regions of a protein

ex) beta pleated sheets and/or alpha helices

tertiary structure

describes the three-dimensional shape of the whole protein

when the protein is functional

Quaternary structure

refers to the structure and organization of a multi-protein complex

hemoglobin

proteins that specialize in binding large fibers are called ___

clamp proteins

proteins that form transporters and channels

pore proteins

proteins that are compact and spherical

globular proteins

proteins forming elongated strands

fibrous proteins

If a protein becomes unfolded or denatured, it will…

become nonfunctional

nucleotides have 3 components. what are they?

5-carbon sugar

one,two, or three phosphate groups, cyclic base

Purines

two ringed cyclic base

guanine and adenine

Pyrimidines

one ringed cyclic base

cytosine,thymine, uracil

the term prime (‘) refers to…

a sugar’s carbons

uracil is only found in..

RNA

thymine is only found in…

DNA

In a nucleotide, a phosphate is exposed at what end?

The 5’ end (five prime)

In a nucleotide, a sugar is exposed at what end?

The 3’ end (three prime)

DNA’s shape is called..

a double helix

The two chains in the double helix of DNA are held together by…

hydrogen bonds

A-T

G-C

true or false: bilayers can not have a hydrophobic edge exposed to an aqueous environment

true

Light microscopy

using visible light to observe cells at high magnification

ex) bright-field microscopes

fluorescence microscope

visualize fluorescent molecule placed inside a cell

Electron microscopy

uses electromagnetic lenses instead of optical lenses to focus beams of electrons on an object rather than light

Scanning Electron Microscope

Used primarily on thicker specimens to look at surface structure

Transmission Electron Microscope

§ Used primarily to look at internal structure by taking slices through a specimen

Flagella is used for..

locomotion

Pili are used for..

exchanging genetic material with other cells

Fimbriae are used to..

attach to a host

Genome

all of the unique chromosomes that are normally found in the cells of a specific species

How many chromosomes are in the human genome?

24

ATP is made from fat and sugar through the process of…

cellular respiration

thick internal fluid in the innermost space of the mitochondria is called..

the matrix

in the mitochondria, the _____ is highly folded which greatly increases its surface area

inner membrane

Detoxification Reactions release what?

release hydrogen peroxide as a by-product, which can be harmful to the cell

Peroxisomes

protect the eukaryotic cells from toxins like alcohol

Rough ER

interconnected system of flattened sacs covered with ribosomes

Ribosome’s function?

build proteins

Lysosome’s function?

recycling centers for an animal cell

Golgi apparatus function?

a factory in which proteins received from the ER are further processed and sorted for transport to their eventual destinations

Smooth ER function?

looks like tubular, interconnected pipes

o Synthesis of glycogen, phospholipids, and steroids.

o Detoxification of medicines and poisons.

o Storage and release of calcium ions.

o Mostly found in liver cells in animals