topic 3 : flashcards

structure of a cell

magnification:

magnification:

the ratio of an object’s image size to its real life

resolution:

the measure of the clarity of the image or minimum distance two distinguishable points

contrast:

visible differences in parts of the sample

basic features of all cells:

1. plasma membrane (boarder)

2. cytosol (semifluid substance in plasma membrane

3. chromosomes (carry genes)

4. ribosomes (make proteins)

the two types of cells:

1. eukaryotic cells

2. prokaryotic cells

eukaryotic cells:

have a nucleus that contains DNA

prokaryotic:

no nucleus

cell wall:

protective layer of extracellular matrix that surrounds the plasma membrane of some cells , just outside the cell membrane

plasma membrane:

selective barrier that allows sufficient passage of oxygen, nutrients, and waste to service the volume of the cell

encloses a cell and separates it from the external environment

the general structure of a biological membrane is made of __________

a double layer of phospholipids

cytosol:

jellylike mixture of water, sugars, ions, and proteins and solutes enclosed by a cell’s plasma membrane

organelles:

structures that carry out special functions inside a cell

nuclear envelope:

covers nucleus

endoplasmic reticulum:

has ribosomes on surface

Golgi apparatus:

modifies proteins

lysosomes:

digest waste and harmful pathogens, can digest some bacteria, viruses, and worn out parts of the cell

vacuoles:

contain water

plasma membrane:

covers cells

cytoplasm:

in a eukaryotic cell, collective term for everything between the cell’s plasma membrane and its nucleus.

DNA includes small units of ____

nucleotides

(A , T , C , G)

function of the cell is dependent on the ______

nucleus that includes DNA

nuclear membrane:

a double membrane where each membrane consists of a lipid bilayer that surrounds the nucleus

nucleus:

contains DNA

ribosomes:

organelle that uses the information from the DNA to make proteins

read the instructions from messenger RNA and assemble materials into a polypeptide

each chromosome is one long _____ associated with proteins

DNA molecules

ribosomes can either be ______ or attached to the _________

free

endoplasmic reticulum

cytoskeleton:

network of fibers extending throughout the cytoplasm;

gives cell it’s structure;

like a highway that allows things to move from one organelle to the next

what do plant cells have that animal cells don’t?

chloroplast / chlorophyll

cell wall

mitochondria:

powerhouse of the cell

double membraned organelle that produce ATP (protein)

cilia:

moves in our windpipe and bronchi of our lungs

traps in debris from getting into our lungs

some bacterial cells have _____ and _____ that helpwith movement and interact with other cells

flagellum and pilus

transport vesicles:

tiny spheres of membrane that surround and carry proteins or lipids to their destination. That destination may be inside the cell, or vesicles may eject their contents out of the cell (exocytosis)

what structure allows only certain molecules to pass into or out of the cell?

cell membrane

what cellular structure contains most of the DNA?

nucleus

which of the following are the only molecules built by ribosomes and rough endoplasmic reticulum (roughe ER)?

proteins

which of the following types of biological molecules are synthesized at the endoplasmic reticulum?

1. proteins

2. lipids

____ & ____ are responsible for breaking down cellular components and molecules

1. lysosomes

2. peroxisomes

on average, eukaryotic cells are approximately _____ larger than prokaryotic cells

10 times

which of the following characteristics is specific to prokaryotic cells?

plasmids

mitochondria are an example of ______

organelles found within eukaryotic cells

which of the following structures are found only in eukaryotic cells? (3)

1. rough ER

2. nuclei

3. Golgi complex

which of the following are parts of both prokaryotic and eukaryotic cells? (3)

1. plasma membrane

2. cytosol

3. DNA

in prokaryotic cells, the DNA is located in the ____ while in eukaryotic cells, DNA is located in the _____.

1. nucleoid

2. nucleus

what part of a phospholipid faces the cytosol inside a cell?

hydrophilic head

ions and polar molecules can cross the plasma membrane in regions where the membrane has incorporated _____

transport proteins

the plasma membrane is considered a fluid mosaic because it permits incorporated molecules such as receptors and transport proteins to _____

move around laterally within the membrane

the word bilayer in the term phospholipid bilayer refers to which of the following

two layers of phospholipids that make up the membrane

the cell membrane is _____ because some molecules can travel across the membrane while others cannot

semipermeable

which small molecule decreases the fluidity of the plasma membrane?

cholesterol