BIOL 4100 - exam 1

Cells vary enormously in ____ and _____

appearance and function

Living cells all have a similar basic chemistry (T/F)

true

living cells are self-replicating collections of __________

catalysts

instructions for the form, function, and behavior of cells and organisms are stored in _______

genes

In all living cells, genetic information flows from ______ to ______

DNA to RNA

All living cells have apparently evolved from different ancestral cells (T/F)

FALSE

The invention of the _______ microscope led to the discovery of cells

light microscope

The fine structure of a cell is revealed by ________ microscopy

electron microscopy

____________ are the most diverse and numerous cells on earth

Prokaryotes

Prokaryotes are divided into two domains:

Bacteria and Archaea

***some bacteria are photosynthetic

Eukaryotic cells possess ______ and _______

nucleus and organelles

Mitochondria generate usable energy from ________ ________.

food molecules

Chloroplasts capture energy from ________

sunlight

The _____________ is responsible for directed cell movements

cytoskeleton

Mitochondria are thought to have evolved from engulfed _______

bacteria

Chloroplasts almost certainly evolved from engulfed _____________ _____________.

photosynthetic bacteria.

____________ __________ create intracellular compartments with different functions

Internal membranes

Eukaryotic cells engage in continual ___________ and __________ across their plasma membrane.

endocytosis and exocytosis

import extracellular materials by _______

endocytosis

secrete intracellular materials by ________

exocytosis

endocytosed material is first delivered to membrane-enclosed organelles called __________

endosomes

The ________ Is a Concentrated Aqueous Gel of Large and Small Molecules

Cytosol

This atomically detailed model of the cytosol of E. coli is based on the sizes and concentrations of 50 of the most abundant large molecules present in the bacterium.

RNAs, proteins, and ribosomes are shown in different colors

The three major types of filaments can be detected using different fluorescent stains.

(A)actin filaments,

(B) microtubules, and

(C) intermediate filaments.

Intermediate filaments are not found in the cytoplasm of cells with cell walls, such as plant cells. (T/F)

true

The ___________ is a network of protein filaments that can be seen crisscrossing the cytoplasm of eukaryotic cells

The cytoskeleton

__________ help segregate the chromosomes in a dividing animal cell

Microtubules

When a cell divides, its _________ ________ breaks down and

Its DNA condenses into visible chromosomes, each of which has duplicated to form a pair of conjoined chromosomes

Chromosomes are pulled apart into separate daughter cells by the spindle ____________.

nuclear envelope

microtubules.

Why don't all cells act and look the same?

gene expression

phase contrast microscope

brightfield microscope w/ stained cells

chronological order of mitochondria evolving (4 steps)

1. bacteria and archaea diverged

2. eukaryote and archaea diverge

3. eukaryotes acquired mitochondria

4. eukaryotes acquired chloroplast

All biological systems are composed of cells containing the same types of chemical molecules and employing similar principles of organization at the cellular level. (T/F)

T

Eukaryotic cells may have originated as ___________

predators

What model organism have molecular biologists focused on?

E. coli

Brewer's yeast is a ______ eukaryote

simple eukaryote

____________ has been chosen as a model plant

Arabidopsis

Model animals include ______, ______, _______, and _____

flies, worms, fish, and mice

Comparing genome sequences reveals life's ________ ________

common heritage

genomes only become genes (T/F)

False

Why have molecular biologists focus on E. coli as their model organism?

easy to grow, grows fast, contains most bacterial structures, easy to manipulate, can accept foreign DNA (singular circular chromosomes, may have some plasmids); pathogenic, non-pathogenic, or a commensal; grows with oxygen or without

Brewer’s yeast (Saccharomyces cerevisiae) is a _________ ________

simple eukaryote

main activities studied through Brewer's yeast (S. cerevisiae)

cell cycle and secretion

Brewer's yeast (S. cerevisiae) model organism benefits

- Exist as both Diploid and Haploid.

- They share many of the more than 6000 proteins with most eukaryotic cells

•Cell cycle

•Protein secretion

Mutations in _________ _________ led to the identification of key cell cycle proteins

Brewer's yeast

uncontrolled cell growth in yeast is similar to what

human cancers

The cell-division-cycle proteins from yeasts and human are very similar in their ________ ________ _________.

amino acid sequences.

Why are Zerbrafish ideal for development studies?

as their transparent embryos develop outside the mother, making it easy to observe cells moving and changing their characters in the living organism as it develop

Confocal microscope, a ________ fluorescent protein marks the developing lymphatic vessels and a ______ fluorescent protein marks developing blood vessels

green

red

Are human cells a model organism?

yes

the first immortal human cell

Hela cells

what is Kit?

both have defects in the same gene (called Kit), which is required for the normal development, migration, and maintenance of some skin pigment cells

Arabidopsis has been chosen as a model _______

model plant

What makes Arabidopsis thaliana a good model organism?

•short generation time and

•the ability to self-fertilize (selfing)

•has a small genome ~114.5 Mb and

•is genetically well characterized due to the volume of work being focused on this plant.

Comparing ________ _________ reveals life's common heritage

genome sequences

cell wall in animal vs. plant vs. bacterial cells

animal cells - no cell wall

plant cells - some have cell wall

bacterial cell wall - has cell wall

eukaryotes share a lot of genetic similarities with humans (T/F)

true

most important characteristics

eye color

what model organism led to the discovery that genes are linked to chromosomes and a specific location on each chromosome?

Drosophila melanogaster - fruit fly

are humans owner of their own cells? common rule

cells detached from the body can be used

The __________ electrons determine how atoms interact

The outermost electrons determine how atoms interact

__________ bonds form by the sharing of electrons

Covalent bonds

*****Covalent bonds are strong enough to survive the conditions inside cells

_________ bonds form by the gain and loss of electrons

Ionic bonds

____________ bonds are important noncovalent bonds for many biological molecules

Hydrogen bonds

_____________ van der Waals attraction bonds for many biological molecules

noncovalent

Cells are made of relatively few types of ________

atoms

Cells contain four major families of small organic molecules, what are they?

sugars, fatty acids, amino acids, nucleotides

_________ are both energy sources and subunits of polysaccharides

Sugars

_______ ________ chains are components of cell membranes

Fatty acid

________ ________ are the subunits of proteins

Amino acids are the subunits of proteins

____________ are the subunits of DNA and RNA

Nucleotides

Two monosaccharides can be linked by a _________ __________ bond to form a disaccharide.

covalent glycosidic bond

In _______________ reaction, two molecules join as a result of loss of water molecule. • Requires an input of energy

Condensation reaction

____________ reaction, water is added and bring the molecules together • Release of energy

Hydrolysis reaction,

In the lipid bilayer is made of __________ phospholipids

• the ______________ heads of the phospholipid molecules are on the outside, facing the aqueous environment, and

• the _______________ tails are on the inside, where water is excluded

amphipathic phospholipids

hydrophilic

hydrophobic

______________, a typical phospholipid, glycerol is covalently linked via a phosphate group to choline.

Phosphatidylcholine,

Phospholipid bilayer is formed by fatty acids linked to glycerol-3-phosphate (G3P) via ______ bonds

via ester bonds

__________ have the most extreme variations in phospholipid sidechain structures.

Archaea

__________ links between glycerol and fatty acids

- Help to grow at high temperature

Ether

Hydrocarbon chains are branched ___________

terpenoids

_________ __________ are the subunits of proteins

Amino acids

Amino acids in a protein are held together by _________ bonds

peptide bonds

_____________ are the subunits of DNA and RNA

Nucleotides

A chain of a deoxyribonucleic acid (DNA) molecule is formed by linking nucleotides with a _______________ bonds

phosphodiester bonds

ATP is synthesized from ADP and inorganic phosphate, and it releases energy when it is hydrolyzed back to ADP and inorganic phosphate.

ATP cycle

_______ is the most common molecule used by cells to capture, store, and transfer energy

ATP

____________ bonds specify the precise shape of a macromolecule and allow a macromolecule to bind other selected molecules

Noncovalent

The _________________ helped to settle the debate about the nature of macromolecules

ultracentrifuge

Both _________ bonds and ______________ bonds are needed to form a macromolecular assembly such as a ribosome.

covalent bonds and noncovalent bonds

A major portion of the energy stored in the chemical bonds of food molecules is dissipated as _______

heat