cells

Question 1

cell theory

Answer 1

1. cells are fundamental units of life
2. all living things are made from cells
3. all cells come from pre-existing cells

Question 2

why are cells so small

Answer 2

cells are small because of the maximization of the surface area: volume ratio

Question 3

structural components to all cells (prokaryotic and eukaryotic)

Answer 3

plasma membrane, DNA, cytosol, and ribosomes

Question 4

function of a ribosome

Answer 4

synthesizes proteins, made of rRNA

Question 5

location of a free and bound ribosome

Answer 5

free: floating inside cell
bound: attached to ER

Question 6

distinguish between prokaryotic and eukaryotic cells

Answer 6

prokaryotic: doesn’t have cell membrane, organelles or nucleus. unicellular, has circular DNA, smaller
eukaryotic: has cell membrane, enclosed organelles, and nucleus. it can be unicellular or multicellular. has linear DNA, larger

Question 7

structural components of all prokaryotes

Answer 7

nucleoid: clustered DNA
cytoskeleton: protein filaments

Question 8

structural components of only some prokaryotes

Answer 8

cell wall: just outside plasma membrane, made of peptidoglycan

capsule: just outside cell wall, slimey layer of carbs
flagella: flapping appendage used for forward movement

Question 9

structural components of all eukaryotes (also endomembrane system)

Answer 9

nucleus
smooth ER
rough ER
golgi body/apparatus
lysosomes
vesicles
plasma membrane

Question 10

what is stored in the nucleus, identify components of nucleus

Answer 10

DNA is stored in the nucleus, functions include DNA replication and RNA transcription
components:
chromosomes: DNA
chromatin: DNA and packing proteins
nuclear pores: allows necessary proteins to enter
nuclear envelope: double membraneci

Question 11

what does the nucleolus produces

Answer 11

production of ribosomes

Question 12

differences between smooth ER and rough ER

Answer 12

smooth ER: functions include production of lipids and steroids, a store house for Ca2+ and detox, has no ribosomes on the surface of the organelle
rough ER: functions include protein production, folding, modification and sorting. it has ribosomes attached to the surface of the organelle

Question 13

functions of the golgi apparatus

Answer 13

functions include protein modification and sorting
*modification: process of covalently attaching chemicals (mostly carbs) to proteins the carbs act as address labels to where the proteins are needed

Question 14

distinguish between the trans and cis face of the golgi, and explain what happens at each side

Answer 14

cis face: (entry) proteins bond to the cis face and are addressed to places where they are needed
trans face: (exit) transport vesicles full of proteins leave the golgi to their destined places

Question 15

explain cisternal maturation model and how it differentiates with the vesicular transport model

Answer 15

cisternal maturation model: dynamic movement of each individual compartments or cisternae.
vesicular transport model: budding to the first cisternae, the attaching to the next, etc. a transport vesicle buds off the last compartment and leaves

Question 16

function of lysosome

Answer 16

removes waste/ old or worn out organelles. involves waste removal and digestion

Question 17

explain processes phagocytosis and autogaphy

Answer 17

phagocytosis: cell (plasma membrane) brings in external materials for digestion of lysosomes through a phagosome
autogaphy: picks up old/worn out organelles, breaks them down and recycles

Question 18

function of mitochondria

Answer 18

functions include cellular respiration and produces ATP

Question 19

structure of mitochondria membranes

Answer 19

intermembrane space (IMS)
matrix: DNA, ribosomes and enzymes

Question 20

function and structure of chloroplasts

Answer 20

functions include absorb light energy and converts it to chemical energy (photosynthesis)
IMS
stroma: liquid in chloroplasts
thylakoid: where photosynthesis takes place
grana/granum: stack of thylakoids

Question 21

function of the peroxisome

Answer 21

acummulate H2O2 and convert it to H2O

Question 22

functions of the central vacuole in plants

Answer 22

storage: waste, posions/bad tasting compounds (defense mechanism), pigments
cell growth/elongation: turgor pressure (firmness of the plant)

Question 23

functions of the cytoskeleton

Answer 23

support and motility (whole cell movement and movement of organelles)

Question 24

similarities/differences between microtubules, intermediate filaments, and micro filaments

Answer 24

microfilaments: thin, solid rods of actin. they support cell shape, like bones but more changeable. ameoboid movement. active filaments shape perimeter of cells
intermediate filaments: tough, rope-like, made of keratin. helps cells withstand mechanical stress. these are permanent, even after cell death
microtubules: thick, hollow tubes made of tubulin. guide organelle movement, separation of chromosomes in mitosis. used in cilia and flagella

Question 25

arrangement of microtubules in fagella/cilia, and the motor protein that drives the flapping movement

Answer 25

‘wagon wheel’ axoneme

• 9 MT doublets around outside
• 2 MT singlets in center
• works with dynein motor protein

Question 26

function and structure in plant cell wall

Answer 26

functions: skeleton of the plant, separate from the cytoskeleton
structure: made up of cellulose, which is strong and fiberous

Question 27

basic structure of the extracellular matrix

Answer 27

(ECM): secreted proteins, collagen and proteoglycans: 5% protein and 95% carbs
-anchored by integin proteins to plasma membrane

Question 28

name and explain intercellular junctions

Answer 28

tight junctions: seal cells so tightly that even fluid cant pass through them
desmosomes: additional support to hold cells together, can withstand mechanical stress, made of keratin
gap junctions: cytoplasmic pores