chapter 6 the importance of cells 1

all cells are related by their? IDK

descent from earlier cells

(idk if this is still right)

all organisms are made of ____, the ____ collection of matter that can support ____.

cell ____ is correlated to cellular ____

cells; simplest; life

structure; function

all organisms are made of cells except for:

viruses and prions

biologists use ____ and the tools of ____ to study cells

microscopes; biochem

cells are extremely ____ although they are usually too ____ to be seen by the ____

complex; small; naked eye

scientists use ____ to visualize cells too small to be seen with the ____

microscopes; naked eye

how do light microscopes (LM) work?

visible light passes thru specimen + glass lenses, which magnify image

the minimum resolution of LMs is about 200 nm, the size of:

a small bacterium

what are our biggest cells?

nerve cells (neurons)

LMs can magnify to about ____ times the size of the actual specimen

1000

various techniques enhance ____ and enable cell components to be ____ or ____

contrast; stained; labeled

most subcellular structures (______) are too _____ to be resolved by a LM

organelles; small

a _____, ____ microscope is most commonly used in teaching + research labs. how does total magnification work?

compound, optical

o Eyepiece: 10x

o Objective: 4x, 10x, 40x, maybe 100x

o Total Mag: 40x, 100x, 400x, maybe 1000x

3 techniques to enhance contrast via staining

1. brightfield (unstained specimen)

2. brightfield (stained specimen)

- what we use

3. phase-contrast

3 techniques to enhance contrast via labeling cellular components for visualization

1. differential-interference-contrast

2. fluorescence

3. confocal

what are electron microscopes used to study?

VERY SMALL particles or cell organelles

electron microscopes (EMs) are used to study:

subcellular structures

2 basic types of electron microscopes

1. scanning electron (SEMs)

- focus electron beam onto surface of specimen, providing images that look 3D

-- scans surface of cell

2. transmission electron (TEMs)

- focus electron beam thru specimen to study internal ultrastructure of cells

what types of microscopes would you use to visualize:

1. human/eukaryotic cell

2. bacterial/prokaryotic cell

3. virus

4. protein

1. light

2. light + electron

3. electron

4. even smaller than electron bc they make viruses

one biochemical technique to study cells is:

isolating organelles by cell fractionation

what does cell fractionation do? what does it enable scientists to do?

takes cells apart + separates major organelles from each other

- enables scientists to determine organelle functions

what do ultracentrifuges do?

fractionate cells into their component parts

what force does cell fractionation use?

centrifugal

ultracentrifuges fractionate ____ from a ___ ___

organelles; cellular extract

eukaryotic cells have internal membranes that ____ their ___.

they also partition the cell into ____

compartmentalize; functions; organelles

the basic structural and functional unit of every organism is one of two cells:

prokaryotic or eukaryotic

only organisms of the domains _____ and ___ consist of prokaryotic cells

bacteria; archaea

(4) consist of eukaryotic cells

1. protists

2. fungi

3. animals

4. plants

4 basic features of both pro and eukaryotic cells (all cells)

1. plasma membrane

2. cytosol (semifluid substance)

3. chromosomes (carry genes)

4. ribosomes (make proteins)

3 aspects of prokaryotic cells

1. no nucleus

2. DNA in nucleoid (unbound region)

3. no membrane bound organelles

3 aspects of eukaryotic cells

1. DNA in nucleus bounded by nuclear envelope

2. larger than pro

3. membrane bound organelles

the logistic of carrying out ____ sets limits on cell ____

cellular metabolism; size

what is the plasma membrane?

selective/semipermeable barrier that allows sufficient passage of oxygen, nutrients, & waste to service volume of cell

the general structure of a biological membrane is _____. what does this allow for?

a double layer of phospholipids; inside and outside of cell

pro vs eukaryotic cells

pro (before nucleus)

- singular circular chromosome

- include bacteria

- flagella for movement (allow 4 invasive infections

- super old/simple

- UNICELLULAR but can form biofilms

eu (true nucleus)

- 46 chromosomes (23 from each parent)

- membrane bound organelles

how does alcohol kill cells?

when you make drugs what should you watch out for?

strip lipids

antibiotic resistance + killing normal flora causes superinfections

why are carbohydrate side chains important?

are antigens that give cells identity

- how ur body knows ur cells r urs vs bacteria

- how sperm find eggs

plant + animal cells have most of the same:

organelles

3 things animal cells have that plant cells don't

1. lysosomes

2. centrioles

3. flagella

5 things plant cells have that animal cells don't

1. chloroplasts

2. central vacuole

3. tonoplast

4. cell wall

- made of cellulose we can't digest but helps digestion

5. plasmodesmata

the eukaryotic cell's genetic instructions are housed in the ____ and carried out by the ___

nucleus; ribosomes

the nucleus contains most of a eukaryotic cell's _____ and the ribosomes use the ____ from this to make ____

DNA; information; proteins

the ______ contains most of the cell's genes and is usually the most ___ organelle

nucleus; conspicuous

the ____ encloses the nucleus, separating it from the ____

nuclear envelope; cytoplasm

central dogma of biology

DNA to RNA (transcription)

RNA to protein translation)

ribosomes are particles made of (2)

1. ribosomal RNA

2. protein

ribosomes carry out protein synthesis in 2 locations:

1. cytosol (free ribosomes)

2. outside ER or nuclear envelope (bound ribosomes)

3 types of RNA

1. messenger RNA

2. ribosomal RNA

3. transfer RNA

how do ribosomes make proteins?

read RNA

the endomembrane system regulates _____ and performs ____ in the cell

protein traffic; metabolic functions

7 components of the endomembrane system

1. nuclear envelope

2. endoplasmic reticulum

3. golgi apparatus

4. lysosomes

5. vacuoles

6. vesicles

7. plasma membrane

components of the endomembrane system are ____ of the cell composed of a ____ that do what?

regions; membrane; transport things btwn diff cell compartments

the plasma membrane encases the ____ and contains the ___ holding all of the ____

entire cell; cytoplasm; organelles

endomembrane system components are either ____ or ____ via ____

continuous; connected; transfer by vesicles

explain 6 parts of the endomembrane system

1. nuclear envelope connected to rough ER, which is continuous with smooth ER

2. membranes + proteins produced by ER flow in transport vesicles to golgi

3. golgi pinches off transport vesicles + vesicles that become lysosomes/vacuoles

4. lysosome available for fusion w/another vesicle for digestion

5. transport vesicle carries proteins to plasma mem for secretion

6. plasma mem expands by vesicle fusion + proteins r secreted

how are proteins made?

1. DNA in nucleus holds cell directions

2. mRNA starts in nucleus bc DNA can't leave

3. mRNA leaves thru nuclear pores into rough ER

4. ribosomes here turn RNA into proteins

cells can either make proteins for itself or send it elsewhere. what are examples of each?

keep: myosin + actin used for muscle contraction

sent: antibodies + mucous sent to battle disease

ur rate of protein production is limited by?

the food u eat

what is the biosynthetic factory?

endoplasmic reticulum

the endoplasmic reticulum (ER) accounts for more than ____ of the total membrane in many ____ cells

half; eukaryotic

the ER membrane is continuous with the ____

nuclear envelope

4 functions of smooth ER

1. synthesizes lipids

2. metabolizes carbs

3. stores calcium

4. detoxifies poison

2 functions of rough ER

1. produces proteins + membranes

2. membrane factory for cell

the rough ER produces proteins and membranes which are distributed by:

transport vesicles

how are the rough ER and smooth ER related?

rough ER makes proteins

smooth ER refines them

the rough ER receives stuff from the ____.

nucleus

ribosomes diff btwn rough and smooth ER

rough: ribosomes bind to/stud its surface

smooth: lacks ribosomes

what part of your body has the most smooth ER?

the liver

the golgi apparatus is like a ____/____ _____ and consists of what?

shipping/receiving center (UPS)

flattened membranous sacs (cisternae)

3 functions of golgi

1. modifies products of the ER (proteins

- post-translational protein modifications are performed in cisternae

2. manufactures certain macros

3. sorts/packages materials into transport vesicles

what are the two faces of the golgi apparatus?

1. cis "receiving"

2. trans "shipping"

what is a cistern? how is this related to the cisternae of the golgi?

cistern: big holding container

rough ER send protein vesicles to cisternae: which hold + modify proteins

lysosomes (____) is a membranous ____ of ____

(digestive compartments); sac; hydrolytic enzymes

hydrolytic enzymes perform ______. lysosomes technically perform a form of _____

hydrolysis; digestion

why are vesicles important for lysosomes?

don't want digestive enzymes outside of vesicles bc they can be harmful

what can lysosomal enzymes do?

hydrolyze proteins, fats, polysaccharides, and nucleic acids

what process can lysosomes do?

digest material taken into cell from outside via phagocytosis

what is the 2nd function of lysosomal enzymes?

recycle organelles + macromolecules within a cell via autophagy

what cells do not have lysosomes?

plant cells

vacuoles (_____) are ____ with varied ___

(diverse maintenance compartments); membrane-bound sacs; functions

a ____ or ____ cell may have 1 or more vacuoles

plant; fungal

food vacuoles are formed by:

phagocytosis

contractile vs central vacuoles

contractile (freshwater protists)

- pump excess water out of cell

central (mature plant cells)

- hold organic compounds + water

____ cells do not have central vacuoles

animal

vacuoles are primarily used for ____ and are only really found in ___ and ___

storage; plants; fungi

vesicles are _____ with varied ____, and are much ____ than vacuoles

membrane-bound sacs; functions; smaller

4 functions of vesicles

1. moving material btwn ER and golgi

2. moving things btwn cisternae of golgi

3. deliver things into cell from extracellular environment via endocytosis

4. deliver waste/hormones to be excreted at exterior of cell via exocytosis

order of how things are transported out of cell by vesicle movement (10)

1. a piece of mRNA is synthesized by transcription from a DNA gene

2. ribosome synthesizes protein by translation (primary structure)

3. protein enters smooth ER to be modified

4. protein folded to form secondary structure

5. protein first enters into vesicle

6. protein enters into cis golgi for modification

7. protein folded to form tertiary/quaternary structures

8. protein transported in transport vesicles btwn golgi's cisternae

9. protein leaves golgi in vesicle

10. vesicle containing protein (mucus, hormones) fuses w/plasma mem to release protein out of cell

vesicles from the ER are sent to the ____ and are ____ so they work, and then (2):

golgi; refined;

1. sent out via exocytosis

2. retained (NOT ENDOCYTOSIS, just retained)

what kind of cells in your body make a lot of protein?

1. muscle

- testosterone makes them stimulate protein synthesis

2. pancreatic

- insulin/glucagon

3. hair

how big is a typical cell?

0.1-0.2 mm / 100 micrometers

why do we fractionate a cell and then centrifuge its parts?

isolating organelles; separates parts of cell to break it down and study them

what are the steps of cell fractionation?

1. homogenization

2. centrifuge

how does a centrifuge sort cellular extract?

based on density

most to least:

1. nuclei and cellular debris

2. mitchondria

3. plasma/internal membranes (microsomes)

4. ribosomes

how does anemia or dehydration affect a centrifuge of blood?

- RBCs usually most dense bc of iron

- anemia makes RBCs lower proportion of blood

- dehydration lowers plasma proportion

a carbohydrate side chain connected to a protein is a:

glycoprotein

lysosomes are filled with _____, a kind of ____.

digestive/hydrolytic enzymes; proteins