Cells Flashcards
1
Q
what is the structure of the nucleus?
A
- has a double membrane, the nuclear envelope which contains pores which allows substances like RNA through
- nucleolus does not have a membrane, it contains RNA
- contains chromatin, DNA wound around histone proteins. the chromatin is the nucleoplasm
2
Q
what is the function of the nucleus?
A
- site of DNA replication and transcription
- nuclear envelope separates the contents of the nucleus from the rest of the cell
- contains nearly all of the genetic material, contains instructions for making proteins/genetic code
- RNA can leave nucleus through pores in nuclear envelope
- nucleolus is where ribosomes are made
- chromosomes contain organisms genes
3
Q
what is the structure of mitochondria?
A
- 2.5um long
-double membrane
-inner membrane is folded into a cristae
-middle space between membranes is filled with fluid called the matrix
4
Q
what is the function of mitochondria?
A
- site of ATP production during aerobic respiration
- have own DNA, ribosomes so can create enzymes for respiration inside organelle
- abundant in cells where much metabolic energy is needed
5
Q
what is the structure of chloroplasts?
A
- large organelles
- only in plant cells
- double membrane
- contain stacks of flattened membrane sacs called thylakoids which contain chlorophyll, each stack of thylakoids is called a grana
- contains the liquid called stoma which contains enzymes, lipids, starch, ribosomes, loops of DNA
6
Q
what is the function of chloroplasts?
A
- site of photosynthesis
- light energy I strapped by chlorophyll and used to make ATP this occurs in the grana
- uses energy from ATP to make carbohydrates occurs in stoma
- chloroplasts are abundant in leaf cells particularly the palisade mesophyll layer
7
Q
what is the structure of the rough endoplasmic reticulum?
A
- network of membranes formed of flattened sheet like sacs called cisternae
- coated with ribosomes
- appears as pairs of parallel lines running through cytoplasm
8
Q
what is the function of rough endoplasmic reticulum?
A
- intracellular transport system: the cisternae form channels for transporting substances
- provides a large surface area for ribosomes to make amino acids into proteins
- transports and modifies ribosomes
9
Q
what is the structure of the smooth endoplasmic reticulum?
A
- system of folded membranes called cisternae
- no ribosomes
10
Q
what is the function of the smooth endoplasmic reticulum?
A
- contains enzymes involved in lipid synthesis
- transport and absorption of lipids
11
Q
what is the structure of the Golgi apparatus?
A
- stack of membrane bound flattened sacs making cisternae
- secretary vesicles pinch off from the cisternae
12
Q
what is the function of the Golgi apparatus?
A
- modifies proteins for example:
adding sugar molecule to make glycoproteins and being folded into their 3D shape - transports proteins by pinching them of in vesicles
- form lysosomes
13
Q
what is structure of a lysosomes?
A
- formed from golgi apparatus
- single membrane
- contain hydrolytic digestive enzymes
14
Q
what is the function of lysosomes?
A
- engulf old cell organelles
- exocytosis
15
Q
what is the structure of cilia?
A
- hairlike projections out of cells
- contains microtubules
- formed from centrioles
