Cell Biology Exam 1

What makes up a single deoxyribonucleotide?

A molecule of the 5-carbon sugar deoxyribose, a nitrogenous base, and a phosphate group

If you want to see the smallest detail on the outside of a cell, what is the best type of microscope to use?

Scanning electron microscope

What are membrane bound compartments within cells?

organelles

Where are organelles found?

in all plant and animal cells

is the nucleus an organelle?

yes

what is true for organelles?

they can have different pH and other environmental features from the cytoplasm

What is present in plant cells but NOT in animal cells?

Chloroplast and Central vacuole

What chemical bond results from sharing of electrons so they orbit both atoms in the bond?

covalent bonds

What are the charges of THR (Threonine), TYR (Tyrosine), SER (serine), GLN (Glutamine), ASN (Asparagine)?

uncharged polar amino acids

what are the charges of ALA (Alanine), GLY (Glycine), VAL (valine), LEU (leucine), ILE (Isoleucine), PRO (Proline), PHE (Phenylalanine), MET (Methionine), TRP (Tryptophan), CYS (Cystine)?

nonpolar amino acids

what are the charges of ARG (Arginine), LYS (Lysine), and HIS (Histidine)?

positively charged polar amino acids (basic)

most enzymes are?

proteins

what type of catalytic activity do enzymes have?

they are catalysts

how do enzymes bind their substrate?

using the active site

how are some enzymes regulated?

using a regulatory molecule and an allosteric site

what happens according to the induced fit model for enzyme activity?

the substrate binding to the enzyme active site causes a shape change allowing the enzyme to better interact with the substrate

When GTP is bound, the protein is

activated

When GDP is bound, the protein is

inactivated

why are enzymes called catalysts of biochemical reactions?

because they reduce the activation energy of a reaction

what is an example of a fibrous protein?

fibroin

what is an example of a globular protein?

hemoglobin

T/F: the binding site for a ligand or substrate is formed from adjacent amino acids in the polypeptide chain

false

what is an enzyme that breaks down proteins called?

protease

what is an enzyme that breaks down nucleic acids is called a?

nuclease

where is the carboxyl end of the polypeptide?

e

Where is the amino acid end of the polypeptide?

b

where is the peptide bond located?

c

how many amino acids are chained together here?

3

what is a cell?

the fundamental unit of life and basic structure (lowest level of organization that can perform all activities required for life)

what are nucleotides?

building blocks for DNA and RNA

what are the building blocks for proteins?

Amino acids

what carries genetic information?

DNA

what is replication?

the process of DNA synthesis

what is transcription?

RNA synthesis

what is translation?

protein synthesis

what is transmission electron microscopy?

electrons are transmitted through the interior of the specimen

what is scanning electron microscopy?

when the surface of a specimen is scanned by detecting electrons deflected from the outer surface

bacteria and archaea are?

prokaryotes

what do prokaryotes lack?

membrane bound organelles, nucleus

what is something prokaryotes have that eukaryotes lack?

cell wall

what is a plant cell wall made up of?

cellulose

what is brightfield light microscopy?

differential interference contrast

what is rough ER?

flattened form of endoplasmic reticulum

what is the smooth ER?

tubular form of ER

what does the rough ER do?

protein synthesis

what does the smooth ER do?

site of lipid synthesis and membrane assembly

what does the golgi apparatus do?

receives and modifies molecules from the ER and sends them in or out of the cell

where are sugars added to proteins?

golgi apparatus

what do lysosomes do?

digest biomolecules

what transports components throughout cells?

small vesicles

what is responsible for muscle contraction?

actin

what type of bond receives and gives electrons between adjacent atoms?

ionic bond

what is a hydrogen bond?

weak bonds between a slight positive hydrogen and slight negative atom

what is a polar covalent bond

the sharing of atoms between two molecules where one atom is more electronegative, so the sharing is unequal (slight +/-).

what is the amino acid formula?

amino groups, alpha carbon atom, carboxyl group, r side chain

what charge do ASP (Aspartic acid), and GLU (glutamic acid have?

(acidic) negative charge

what is the structure of a nucleotide?

a five-sugar base attached to a phosphate group and a nitrogenous base

what bases are different in RNA and DNA?

Thymine (DNA) and Uracil (RNA)

what are the functions of proteins?

catalyze chemical reactions, provide structural support, regulate membrane permeability

how do amino acids chain together

within a protein, linked by peptide bonds

what is primary structure?

amino acid sequence

what is secondary structure?

folding into alpha helix and beta sheets

what is tertiary structure?

3D folding of a single polypeptide chain

what is quaternary structure?

multiple polypeptides forming

what are cofactors?

protein components needed for protein function

what is another word for ligand?

substrate

what are globular proteins?

folded into compact tertiary sstructures

what are fibrous proteins

extensive regions of secondary structures that are given a highly ordered repetitive structured

what are allosteric proteins?

can cause shape change and can either help site function or prevent it

what is a protein domain

locally folded unit of a tertiary structure with a specific function

what does kinase do?

adds phosphotase

what does phosphotase do?

removes phosphate group

cut the py

cytosine, uracil, thymine = pyrimidine

GA the pur

guanine, adenine= purine

what is a nucleoside

a base covalently bonded to sugar with no phosphate group

what direction are 5’ and 3’

antiparallel

where does binding occur?

3’ OH

what is the difference between RNA and DNA nucleotides?

RIBOSE sugar (RNA) and DEOXYRIBOSE sugar (DNA)

what are chromosomes

proteins with a single molecule of DNA

what is a genome?

information contained within the organism’s DNA

what type of DNA has circular chromosomes?

prokaryotic

what is an RNA and DNA hybrid

r loop

what is the process of prokaryotic RNA transcription

binding, initiation, elongation, termination

what does RNA polymerase do?

copies DNA sequence into RNA sequence

what is the promoter

where RNA polymerase first binds

what is the terminator

the end of transcription region

what type of bond holds together beta plated sheets

hydrogen bonds

why are enzymes catalysts of biochemical reactions

they reduce the activation energy of a reaction

where does a competitive inhibitor bind to an enzyme?

active site

what is the +1 site of a gene

where the first nucleotide of RNA is encoded

the enzyme that synthesizes most mRNA in prokaryotes is

RNA polymerase (no number)

the enzyme that synthesizes most mRNA in eukaryotes is

RNA polymerase II