bio test 1

Phagocytosis

"food" molecules, viruses, or bacterial cells

how are DNA and RNA structurally different

(1) the sugar in RNA is ribose not deoxyribose; (2) RNA is generally single-stranded and not double-stranded; (no helix) (3) RNA contains uracil in place of thymine.

evidence supporting for endosymbiosis

-Both organelles are like bacteria in size and structure. -Both organelles are bounded by a double membrane. -The outer membrane may be derived from the engulfing vesicle. -The inner one may be derived from the plasma membrane of the original prokaryote. -Both organelles contain a limited amount of genetic material and divide by splitting. -Their DNA is a circular loop like that of prokaryotes. -They have their own ribosomes and produce some proteins. -Their ribosomes resemble those of prokaryotes. -The RNA (ribonucleic acid) base sequence of the ribosomes in chloroplasts and mitochondria also suggests a prokaryotic origin of these organelles.

cell theory

1. all living things are composed of cells, 2. cells are the basic units of structure and function in living things, 3. new cells are produced from existing cells

ionic bond

A chemical bond resulting from the attraction between oppositely charged ions. (NaCl)

covalent bond

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

polar covalent bond

A covalent bond in which electrons are not shared equally

hypertonic

A solution has a higher solute concentration than the inside of a cell. Cell loses water and shrinks (crenation or plasmolysis occur)

hypotonic

A solution has a lower solute concentration than the inside of a cell. Cell gains water and swells up (lysis of cell may occur)

electron

A subatomic particle that has a negative charge

proton

A subatomic particle that has a positive charge and that is found in the nucleus of an atom

neutron

A subatomic particle that has no charge and that is found in the nucleus of an atom

element

A substance that cannot be broken down into simpler substances

You find yourself standing next to a beautiful rose bush. Which of the following do you and the rose have in common? A) You both are multicellular. B) You both lack a membrane-bound nucleus. C) You are both prokaryotic. D) You and the rose have nothing in common.

A) You both are multicellular

What molecule is composed of one or more sugars? A) carbohydrate B) lipid C) nucleic acid D) polypeptide

A) carbohydrate

Which element is the basis for the macromolecules found in living things? A) carbon B) hydrogen C) nitrogen D) oxygen

A) carbon

Which of the following is a producer? A) oak tree B) earthworm C) sun D) cat

A) oak tree

If you disrupt all hydrogen bonds in a protein, what level of structure will be preserved? A) primary structure B) secondary structure C) tertiary structure D) quaternary structure

A) primary structure

endomembrane system

Acts as the transportation and product-processing section of the cell. Compartmentalizes cell so that enzymatic reaction restricted to specific cell sections

Adhesion junctions

Adhesion proteins connect cytoskeletal filaments of adjacent cells.

isotopes

Atoms with the same number of protons but different numbers of neutrons

hydrophilic

Attracted to water

. Where are carbohydrates and phospholipids made within a cell? A) Rough endoplasmic reticulum B) Smooth endoplasmic reticulum C) Golgi apparatus D) Lysosomes

B) Smooth endoplasmic reticulum

A researcher hypothesized that tributyltin (an additive in boat paint) causes reproductive defects in marine snails developing in the water. In an experiment testing the effects of tributyltin on developing snails, which condition should be used as a control? A) Snails developing in a water tank are exposed to extremely low levels of tributyltin. B) Snails developing in a water tank are exposed to boat paint without tributyltin. C) Developing snails are kept in a dry tank to avoid exposure to contaminated water. D) Developing snails are kept in a water tank cleaned with chlorine bleach.

B) Snails developing in a water tank are exposed to boat paint without tributyltin.

What happens when the concentration of a solute is equal on both sides of a plasma membrane? A) The particles will begin to move against the concentration gradient. B) The net movement of particles through the plasma membrane will stop. C) The cell will continue to grow until it finally bursts. D) The cell will begin to shrink because the water levels are not equal.

B) The net movement of particles through the plasma membrane will stop

What results from an unequal sharing of electrons between atoms? A) a nonpolar covalent bond B) a polar covalent bond C) an ionic bond D) a hydrophobic interaction

B) a polar covalent bond

Imagine a newly discovered biological molecule that is mostly hydrophobic in its structure. How would this new molecule be classified? A) carbohydrate B) lipid C) nucleic acid D) protein

B) lipid

Which macromolecule has a sugar-phosphate backbone? A) lipid B) nucleic acid C) protein D) polysaccharide

B) nucleic acid

. What kinds of molecules pass through a cell membrane most easily? A) large and hydrophobic B) small and hydrophobic C) large polar D) ionic

B) small and hydrophobic

The newly synthesized proteins are transported from the endoplasmic reticulum to the Golgi apparatus by________. A) cilia B) transport vesicles C) endocytosis D) gated channels

B) transport vesicles

. How many electrons are involved in a single covalent bond? A) one B) two C) three D) four

B) two

A solution with a pH of 6 has ________ times as many hydrogen ions as a solution with a pH of 8. A) 2 B) 10 C) 100 D) 10,000

C) 100

The second electron shell of an atom can hold a maximum of ______ electron(s). A) 1 B) 2 C) 8 D) 18

C) 8

Which feature is found in both prokaryotic and eukaryotic cells? A) mitochondrion B) Golgi apparatus C) DNA D) chloroplast

C) DNA

Which of the following is an acid? A) NaOH B) NaCl C) HCl D) CH4

C) HCl

Imagine a balloon is made from a membrane that's permeable to water but not sugar molecules. How would the balloon be affected if it is filled with a 50% sugar solution and then placed in a beaker of water? A) The balloon would not change in size or volume. B) The balloon would get smaller as it loses water. C) The balloon would get larger as it gains water. D) The balloon would eventually burst.

C) The balloon would get larger as it gains water.

. Which of the following types of cells utilize deoxyribonucleic acid (DNA) as their genetic material but do not have their DNA encased within a nuclear envelope? A) animal B) plant C) bacteria D) Fungi

C) bacteria

How would amino acids and calcium ions from the bloodstream move across a plasma membrane? A) active transport B) diffusion C) facilitated transport D) osmosis

C) facilitated transport

What kind of molecule forms the bilayer found in cellular membranes? A) carbohydrate B) cholesterol C) phospholipid D) protein

C) phospholipid

cell junctions

Cell surfaces in certain tissues of animals have junctions between cells

. You find a cell of a type you have never seen before. The cell has both a nucleus and a cell wall. Therefore, you conclude that it must be a __________ cell. A) prokaryotic B) animal C) bacterial D) plant

D) plant

Which type of macromolecule is present in enzymes? A) carbohydrates B) lipids C) nucleic acids D) proteins

D) proteins

Osmosis

Diffusion of water through a selectively permeable membrane

structure of chloroplast

Double membrane. Stroma—fluid-filled space bounded by double membrane. Contains single circular DNA molecule and ribosomes. Membrane system of sacs called thylakoids. Grana—stacks of thylakoids. Chlorophyll located in thylakoid membranes.

centrioles

Found in centrosomes of animal cells

cilia and flagella

Hairlike projections that aid in cell movement

Eukaryotic

Larger More complex Genetic materials are stored in nucleus Have membrane-bound organelles Found in all other living things,

phospholipid molecule

Main component of the lipid bilayer Consists of - a polar head (hydrophilic) and - 2 hydrophobic tails

peroxisomes

Membrane-bound vesicles containing enzymes. Actions of enzymes produce hydrogen peroxide (H2O2). H2O2 quickly broken down into water and oxygen by the enzyme catalase.

endosymbiotic theory

Mitochondria and chloroplasts derived from prokaryotes that were taken up by larger cells. Mitochondria were originally heterotrophic bacteria. Chloroplasts were originally cyanobacteria. After entering the host cell, the bacteria began living together cooperatively.

diffusion

Movement of molecules from an area of higher to lower concentration Down a concentration gradient. Occurs until equilibrium is reached.

What are the steps involved in a scientific method?

Observe and generalize Formulate a hypothesis Make a testable prediction Experiment or observe Modify hypothesis if needed and repeat

example of cilia

Paramecium

gap junctions

Plasma membrane channels of cells join, allowing communication and strength

tight junctions

Proteins connect plasma membranes of adjacent cells to form impermeable barriers.

Prokaryotic

Smaller Simpler Genetic materials are stored in nucleoid Do not have membrane-bound organelles Found in bacteria and archaea

atom

Smallest particle of an element

isotonic

The solute concentration is equal inside and outside a cell. No net gain or loss of water inside the cell

"The plasma membrane selectively permeable" what does this statement mean

This means that only certain molecules can freely cross the membrane and others may require carrier proteins and energy to cross the membrane

active transport

Transport charged molecules against their concentration gradient. Accumulate either inside or outside the cell. Highly specific, requires carrier proteins. Energy is required

hydrophobic

Water fearing

plant vacuoles store

Water, sugars, salts. Pigments. Toxins.

nonpolar covalent bond

a covalent bond in which the electrons are shared equally by the two atoms

extracellular matrix

a meshwork of structural proteins and polysaccharides closely associated with cells that produced them.

polar molecule

a molecule in which one side of the molecule is slightly negative and the opposite side is slightly positive

receptor mediated endocytosis

a type of pinocytosis involving pits coated with receptor proteins for specific molecules

cytoseleton consists of what three interconnecting proteins

actin filaments intermediate filaments microtubules

carrier proteins

allow the passage of a solute by combining with it and helping it to move across the membrane.

monomers of proteins

amino acids

base

any molecule that can accept hydrogen ions or release OH ions

acid

any molecule that can donate hydrogen ions (H+) or protons

All carbohydrate molecules

are composed of atoms of C, H, and the functional group -OH.

peripheral proteins

associated with only on side of membrane

Levels of Biological Organization

biosphere ecosystems communities populations species organisms organ systems organ tissue cell molecule atom

Hydrolysis of a fat results in

both glycerol and fatty acids.

buffer

chemical or combination of chemicals that keep pH within normal limits

what molecule adds stiffness and strength to the plasma membrane

cholesterol

structural proteins in ECM are

collagen elastin fibronectin proteglycans

lipid bilayer (plasma membrane)

composed of two layers of phospholipid molecules Defines cell boundary and isolates cell contents from environment. Membrane proteins are embedded in the membrane. Sugar chains are attached to both phospholipids and membrane proteins

bond that defines tertiary structure

covalent, ionic, disulfide, and hydrogen

Categories of classification

domain kingdom phylum class order family genus species

endocytosis

enter into the cell Cells take in large substances by endocytic vesicle formation

exocytosis

exit from the cell The vesicle fuses with plasma membrane as secretion occurs. The vesicle membrane becomes part of the plasma membrane. (ex. pancreatic cells, anterior pituitary cells)

facilitated transport

explains the passage of charged molecules such as glucose or amino acids down the concentration gradient Highly specific, carrier protein undergoes change in shape. Does not require energy (ATP) to drive the molecule

cristae

formed by the invagination of the inner membrane in mitochondria

Which components of a cell membrane are used for cell-to-cell recognition?

glycoproteins

cell recognition proteins

glycoproteins. These proteins help the body recognize when it is being invaded by pathogens.

Mictrotubules

hollow cylinders maintain cell shape, help in moving organelles and forming spindle apparatus during cell division

bond that defines secondary structure

hydrogen bond

matrix

inner fluid filled space of the mitochondrion

channel proteins

involved in the passage of solutes through the membrane. Some may contain a gate that must be opened in response to a signal

6 characteristics of life

life is organized life requires materials and energy life has the capacity to reproduce and develop life responds to its environment life maintains an internal environment life has the ability to adapt

glycolipids

lipids with attached carbohydrates

Pinocytosis

liquid and small particles

relationship between monomers and polymers

monomers make up polymers

monomers of carbohydrates

monosaccharides

Ribosomal RNA is produced in the

nuceolus

what organelles are a part of the endomembrane system

nuclear envelope, endoplasmic reticulum, golgi apparatus, and several vesicles

monomers of nucleic acids

nucleotides

bond that defines primary structure

peptide bonds

what are the three types of endocytosis

phagocytosis, pinocytosis, receptor-mediated endocytosis

Four levels of protein structure

primary, secondary, tertiary, quaternary

glycoproteins

proteins with attached carbohydrates

actin filaments

provide structure as dense web under plasma membrane

tonicity

relative concentration of solute outside the cell as compared to inside.

how does the endomembrane system work

rough ER synthesizes, processes, and folds proteins and the smooth ER synthesizes lipids and performs various other functions. Transport vesicles budding off the rough ER and smooth ER shuttles proteins to the golgi apparatus. Golgi apparatus modifies lipids and proteins from the ER and sorts and packages them into vesicles. secretory vesicles bud off from the golgi and carry molecules to the plasma membrane, where secretory vesicles fuse with the plasma membrane for secretion of the materials. Lysosomes contain digestive enzymes that break down worn out cell parts or substances entering the cell at the plasma membrane via incoming vesicles.

intergral proteins

span the membrane. can protrude from one or both sides. embedded within the membrane. able to move laterally

example of flagella

sperm

intermediate filaments

support nuclear envelope and help forming cell-to-cell junctions

hydrogen bond

the attraction between a partially negative oxygen in one molecule and a partially positive hydrogen in another molecule

atomic number

the number of protons in an atom

fluid mosaic model

the pattern of phospholipids, steroids, and proteins in the membrane.

mass number

the sum of the number of neutrons and protons in an atomic nucleus

bond that defines quaternary structure

two or more polypeptide chains