Cellular Biology Flashcards
1
Q
describe cel theory
A
- all living things are ocmposed of cells
- a cell is the basic functional unit of life
- chemical reactionf of life take place inside the cell
- all cells arise from pre-existing cells
0 cells carry info in form of DNA, genetic info is passed from parent cell to daughter
2
Q
what are the 6 kingdoms
A
archaea, protista, fungi, plantae and animalia
3
Q
function of cell membrane
A
- plasma mem, selectively permeable
- fluid mosiac model: phospholipid bilayer with embedded proteins (phosphorous containing polar heads face out and hydrocarbon tails in)
- permeable to small hydrophobic mol like oxygen and small polar mol liek water
- others transported w/ carrier proteins
4
Q
function of the nucleous
A
- controls cell activites and division
- contains DNA complexed w/ histones to form chromosomes
*histones also involved in gene transcription
- also contains nucleolus where ribosomal synthesis occurs
5
Q
Function of ribosome
A
protein synthesis
- free in cytoplasm or bound to ER
6
Q
function fo ER
A
- tranport of materials particular those to be secreted
- smooth inolved in metabolism and production of lipids
- rough ER plays role in protien production
7
Q
function of Golgi apparatus
A
receives vesicles from smooth ER and modfies tthem and repackages into vesicles
- distributes to cell surface via exocytosis
8
Q
function of mitochondria
A
aerobic respiration: energy supplier mainly in fomr of ATP
- has outer and inner phospholipid bilayer
9
Q
function of cytoplasm
A
- where most metabolic activity occurs
- transport within occurs via cyckidud (streaming movement within cell)
10
Q
function of vaculoes/vesicles
A
membrane bound saces involed in transport and storage that are ingested, secreted, processed or digested by the cell
- vaculoes larger than vesicles
11
Q
function of centriole
A
- spindle organization during cell division
- typically pair of centrioles at right angles to each other in centrosome
- only in animal cells
12
Q
function of lysosomes
A
- membrane bound vesicles contining hydrolytic enzymes
- involved in intracellular digestion
- rupturing lysosome to release hydrolytic enzymes for autolysis (cell suicide)
13
Q
function of cytoskeleton
A
- supprts cell, maintians shape and aids in motility
- comprised of microtubules, microfilaments, and intermediate filaments
Microtubules = hollow rods of polymerized tubulun that radiate throughout the cell providing support and framework for organelle movement in cell
- centrioles comprised of microtubules
- cilia and flagella are specialized arrangements of microtubules
- microfilaments = solid rods of actin impmortant for cel movement and support
14
Q
simple diffusion
A
- net movemnt of particles down their concentration gradient, no energy
- ex = Osmosis, diffusion of water from lower solute conc to higher solute conc
15
Q
hypertonic
A
- call cytoplasm has lower solute conc then outside, water will flow out and cell will shrivel
- also caled plasmolysis
16
Q
hypotonic
A
- extracellular environment less conc then cytoplasm so water flow into cell
- cell wil swell and lyse (burst)
ex: rbc will burst if placed in distilled water
17
Q
isotonic
A
extracellular environemnt ahs same conc as inside cell
- water moves back in fourth
18
Q
facillitated diffusion
A
- passive transport
- net movement down conc gradient via carrier protein
- still no energy
19
Q
active transport
A
- energyrequired to move against conc gradient via transport protein
- general carrier molecules include:
- energy-independent carriers: facilitate movement of compounds along gradient
- symporters: move two or more ions or mol in same direction
- antiport_ exchange of one or more mol or ions for another across membrane
- pumps: energy dependent carriers
20
Q
endocytosis
A
- cell membrane invaginates forming vesible that contains extracellular medium
- allows to bring large volumes of extracellular material inside the cell
Pinocytosis: ingetion of fluids or small particles
Phagocytosis: englufing large particles
21
Q
exocytosis
A
vesicle in cell fuses with membrane to release a large volume of contants to the outside
ex. occurs wth neurotransmitters
22
Q
bownian movement
A
- intracellular circulation
- kinetic energy spreads small suspended particles throughout the cytoplasm of cell
23
Q
cyclosis or streaming
A
- ex of intracellular circulation
- circular motion of cytoplasm around the cell transports molecules
24
Q
Endoplasmid reticulum for intracellular circulation
A
forms a network of chennels throughout the cytoplasm providing a direct continuous pathway from the plasma membrane to nuclear membrane
25
examples of extracellular circulation (movement of materials on larger scale thoguh body)
**Diffusion:**
* occurs if cells are in direct or close contact w/ external environment
**Circulatory System**:
* complex animals whos cells are too far from external environment to transport via diffusion
* requires circulatory system
* includes vessels to transport fluid and a pump to drive circulation
26
importance of cell division for unicellular vs multicellular organisms
unicellular: means of reproduction
multicellular: means of growth, developemnt and replacemnt of cells
27
what is interphase
- period of growth and chromosomal replicaiton
- accounts for 90% of lifetime
- after replication chromosome consists of two sister chromatids held together by centromere
\*during interphase individual chromosomes are not visible, DNA is celled chromatin
28
what are the parts of interphase
G1: initiates interphase, described as the active growth phase and can vary in length, cell increases in size and synthesizes proteins
\*length of G1 determines lenght of entire cell cycle
S: period of DNA synthesis
G2: cell prepares to divide, it growth and synthesizes proteins
M: mitosis or meiosis
29
30
what it mitosis and the 4 phases
division and distribution of cells DNA into two daughter cells
- each cell recieves a complete copy of original genome
- occurs in somatic cells (not gametes)
\*nuclear division (**karyokinesis)** is followed by cel division **(cytokinesis)**
31
what is karyokinesis
nuclear division
32
explain prophase
chromosomes condense and centriole pairs (in animal cells) separate and mvoe towards opposite ends of the poles of cell
- spindle apparatus forms between them and nuclear membrane dissolves allowing spindle fibers to interact with chromosomes
\*PMAT
33
explain metaphase
- centrioles are at opposite poles, fibers of spindle apparatus attach to each chromatid at coresponding **kinetochore** (a protein location on the centromere)
- the spindle fibers align the chromosomes at the centre of the cell (equator) forming the **metaphase plate**
34
explain anaphase
- centromeres split so each chromatid has tis own distinct centromere, allowing sister chromatids to separate
- sister chromatids are pulled twds opp ends of poles y shortening of spindle fibers
\*spindle fibers are composed of microtubules
35
explain telophase
- spindle apparatus disspears
- nuclear memrane forms around each set of newly formed chromosomes
\*each nucleus contains the same number (diploid 2N) as the original parent
- chromosomes uncoil
36
what is cytokinesis
cell division
- near end of telophase cytoplasm divides into 2, each with a complete nucleus and set of organelles
- in animal cells a **cleavage furrow** forms and cell membrane indents along euator, pinches the cell itno 2
- in plant cells a **cell plate** forms between the two nuclei, spilling it in half
37
explain meiosis
- sexual reporduction: requires two parents
- occurs via fusion of teo gametes produced by each parent
- produces haploid **1N** cells halving the number of chromosomes
- involves two divisions resulting in 4 gametes
38
interphase of meiosis
- like mitosis, parent cells chromosomes are replicated resulting in 2N number of sister chromatids
39
what is the product of the first meiotic division
- two intermediate daughter cells with N chromosomes and sister chromatids
40
explain prophase 1 meiosis
- chromatin condenses into chromosomes
- spindle apparatus forms and nucleoli and nuclear membrane disappear
- homologous chromosomes come together and intertwine (**synapsis**)
\*each chrom has 2 sister chromatids, each synaptic pair consists of 4 chromatids so called **tetrad**
\*chromosomes can break and cross over to exchange genetic info, the points of contact between homologous chromosomes where crossing over occurs = **chiasmata**
- sister chromatids no longer identical after crossing over has ocurred
41
explain metaphase 1 meiosis
- homologous pairs (tetrads) align at equatorial plane and each pair attaches to a separate spindle fiber at the kinetochore
42
explain anaphase 1 meiosis
- homologous pairs separate and pulled to opp ends of cell (disjunction)
- paternal ones in one and maternal ones in other, get genetic variability due to previous crossing over
43
explain telophase 1 meiosis
- nuclear membrane forms around each new nucleus
\*each chromosome still consists of sister chromatids joined at centromere
44
what is the product of the second meiotic division
- similar to mitosis but meiosis II is not preceed by chromosomal replication
- get haploid number of chromosomes
\*note in woman only one of these daughter cells becomes a functional gamete the other two or three are destroyed by the body
