BIOL Chapter 3: Cells

what type of cell membrane proteins binds molecules on the cells exterior which triggers a reaction in the cells interior

receptor proteins

what is a correct description of a confocal microscope?

white or a laser light is focused through a lens, and the image passes through a pinhole

which of the following are examples of high surface area being advantageous to an organism?

- large surface area in fish gills - large leaves in a light-poor environment - pollen grains with extensions in a wind pollinated plant

functions of organelles in eukaryotic cells

-allows for high concentration of biochemicals only in certain cell areas -improve efficiency of cell functions -keep related biochemicals in close procimity to each other

components of cell membranes

-proteins -phospholipids -steroids

Select all that are true about organisms in Domain Bacteria

-some live in human intestines and help with digestion -important decomposers and producers -Earth's oldest organisms -some are used to make pharmaceuticals

the smallest object that the unaided human eye can see are about ______ in size.

0.2 mm

The _______ theory states that all life is composed of one or more cells, which ate the fundamental unit of life

Cell

in a cell, ________ is the genetic information of the cell, and RNA play a role in the production of _______

DNA; proteins

why would the number of organelles in a cell vary depending on the type of cell?

Different types of cells have different amounts of some organelles. For instance, cells that use a lot of energy tend to contain large numbers of mitochondria

The requirement that specimens be killed and chemically fixed is a limitation of

Electron microscopy

key genetic sequences suggest that archaea are more closely related to members of domain ______ than they are to members of Domain Bacteria.

Eukarya

why cells are limited with regard in size?

limited by surface are to volume ratio. A smaller cell is more effective in transporting materials.

what are the four major components of plasma membrane

lipids, proteins, carbohydrates,

all cells have a cell ______ that surrounds the cytoplasm and forms a boundary between the cell and its environment

membrane

the cytoplasm of eukaryotic cells includes many specialized compartments called

organelle

all cells are surrounded by cell membranes, also called plasma membranes, that separate the cytoplasm from the

outside environment

biological membranes are selectively ______ meaning they allow only specific types of molecules to pass into or out of the cell

permeable

the cell membrane is composed of a type of lipid molecule call a(n) _______ which has two fatty acids and a phosphate group extending from a glycerol molecule.

phospholipid

what four components do both prokaryotes and eukaryotes have?

plasma membrane, ribosomes, cytoplasm, and DNA

what type of microscope has the highest resolution and can resolve objects less than 1 angstrom apart?

Transmission electron microscope (TEM)

true or false: most cells have a small size that is than .1 mm in diameter to maximize surface area relative to volume

True

A eukaryotic cell is different from a prokaryotic cell in that it contains

a nucleus

proteins on the surfaces of cell membrane which enables cells to stick to other cells are called ____ proteins.

adhesions

mitochondria and chloroplasts

both contain DNA and ribosomes Mitochondria- internal membrane structure is Cristae, produce ATP, nearly all eukaryotic cells Chloroplasts- internal membrane structures thylakoids, produce sugar, eukaryotic cells that carry out photosynthesis.

why are the mitochondria and chloroplasts considered endosymbionts?

both contain their own DNA and ribosomes

what is the smallest unit of life that can function independently

cell

Schleiden, Schwann and Virchow are the three scientists credited with formulating the components of the

cell theory

in some bacteria, the capsule is a protective layer that forms from polysaccharides on the

cell wall

what surrounds the cell membrane of most bacteria and provides structure and protection

cell wall

whether bacterium or blue whale, every organism is made of

cells

what is a steroid molecule that is found in animal cell membranes and that maintains membrane fluidity.

cholesterol

what is the network of protein fibers and tubules inside the cell that inside the cell that provides support and aids in cell division and movement?

cytoskeleton

proteins that increase the speech of chemical reactions on the cell membrane and in other parts of the cell are called _______.

enzymes

in some types of bacteria, appendages called _______ rotate like a propeller and allow movement forward and backward

flagella

the cell membrane can be described as a(n) ________ mosaic because many of the diverse components can move freely within the cell membrane

fluid

what is the function of recognition proteins in the plasma membrane?

identify the cell as belonging to the body and a certain tissue type

what would happen if this membrane were completely permeable? completely impermeable?

if permeable; any substance can enter cell if impermeable, not letting anything in the cell

the phosphate head end of a phospholipid is _________ meaning its polar covalent bonds attract water, but the tails of a phospholipid are _____ and thus face away from water

hydrophilic; hydrophobic

what english physicist first observed the outlines of cells when he looked at cork from an oak tree?

Hooke

in prokaryotic cells, DNA congregates in an area called the

Nucleoid

what does it mean for the phospholipid bilayer to be semipermeable?

Only certain molecules can pass though by facilitated diffusion, active transport, or passive transport

compare and contrast prokaryotes and eukaryotes

Prokaryotes: -have NO nuclei -DNA exists as a single, circular strand -DNA is located in the "nucleotide", an area without a protective membrane -have no organelles wrapped in membranes -ribosomes are smaller than those of eukaryotes -don't have microtubules in their flagella/cilia -plasma membrane is made of peptidoglycans, aka protein-sugars Eukaryotes: -have a nucleus -DNA exists as many strands -nuclear envelope surrounds the nucleus -organelles are wrapped in membranes -bigger than prokaryotic cells -have microtubules in flagella/cilia -plasma membrane made of phospholipids Both: -have cytoplasms, plasma membranes, ribosomes, DNA

_______ cells are the simplest forms of life and lack a nucleus

Prokaryotic

_______ microscopes bounce electrons off the outside of a metal coasted three dimensional object to observe the exterior texture

Scanning electron

A ________ cell can exchange materials with the environment more efficiently than can a ______ cell.

Small; large

what type of cell membrane protein allows molecules and ions to enter or exit the cell?

transport proteins