Cell biology Flashcards
Animal cell contents
Lysosome, golgi body, mitochondria, centriole, ribosomes, RER, cell membrane, nuclear pore, nucleolus, chromatin, nuclear envelope, vesicle
Plant cells content
Nucleolus, vacuole, cell wall, cell membrane, mitochondria, chloroplast, golgi body ribosomes, cytoplasm, nucleus, SER, plasmodesma, nucleus pore and envelope, tonoplast
nucleus
Contains DNA codes for protein synthesis- Site of transcription
DNA also provides templates for DNA replication
Bounded by two membranes- envelope, pore: Allows passage of large molecules eg. Mrna
outer membrane is continuous with endoplasmic reticulum
Within the nucleus
Granular material in nucleus is nucleoplasm containing chromatin- made of coils of DNA bound to protein during cell division.
condenses into chromosomes
Within the nucleus are 1 or more small spherical bodies called nucleolus
mitochondria content
Matrix, outer membrane, inner membrane space, inner membrane, 70S ribosomes, cristae, DNA
Function of mitochondria
produces ATP in aerobic respiration
Inter membrane space- mitochondria
2 membranes separated by a narrow, fluid filled inter membrane space
Inner membrane is folded inwards to form cristae
organic matrix- mitochondria
definition
solution containing compounds eg. Lipids, proteins
Circle of DNA- mitochondria
So mitochondrion can replicate and code for some of its proteins and RNA
70s ribosomes- mitochondria
allows protein synthesis
Functions of features- mitochondria
Some reactions occur in the matrix and other in the inner membrane
Christie provides large service area for attachment of enzymes involved in respiration
Cylinder shape reduces diffusion distance between the edge and the centre- Making aerobic respiration more efficient
muscle cells contain lots of mitochondria as they require more energy for frequent relaxation and contraction
function of chloroplast
Occur in the cell of photosynthesizing tissue
Chloroplast content
Each chloroplast is surrounded by two membranes comprising chloroplast envelope
Stroma- Fluid filled containing some products of photosynthesis
70s ribosomes and circular DNA- Enable them to make some of their own protein and self replicate
within the stroma
- flattened sacs called thylakoids
- stack of them called granum’s
-chlorophyll found in thylakoids - arrangements produces large SA efficient for trapping light energy
Endoplasmic Reticulum
Parallel double membranes forming flattened sacks with interconnected fluid filled spaces between them- cisternae
rough ER (RER)
Has ribosomes on the outer surface transporting proteins made there
80s manufacturers and transport proteins
smooth ER (SER)
Comprises membranes that lack ribosomes, associated with transportation and synthesis of lipids
ribosomes
1 large and 1 small subunit
Assembled in a nucleus from rRNA and protein
Involved in protein synthesis
70s found in bacteria and mitochondria
80s in RER
Golgi body function
processes and packages proteins
Golgi body features
vesicles- contain polypeptides, pinch off RER fusing with stack of membranes, which constitute the golgi body
At the other end of the Golgi, vehicles containing modified proteins are pinched off.
May carry proteins elsewhere in the cell or move to and fuse with the cell membrane, secreting modified proteins by exocytosis
Lysosomes
Small temporary vacuole surrounded by a single membrane- Formed by being pinched off from the golgi body
Lysosome functions
Contain and isolate potentially harmful digestive enzymes from the remainder of the cell
Get rid of all damaged organelles by surrounding and digesting them
Digest material taken into the cell
Involved in cell death
Eg. They fuse with a vesicle when white blood sell engulfs bacteria by phagocytosis and their enzyme digest bacteria
Centrioles- in animal cells
Located just outside the nucleus
Two rings of microtubules make hollow cylinders positioned at right angles to one another
centriole function
Cell division- Centrioles organised microtubules to make the spindle
Vacoule
Fluid filled sac
Bounded by a single membrane- tonoplast
Contain sap
vacuole function
maintains turger your pressure and keeps the cell firm