chapter 3 - cells Flashcards
1
Q
what is the cytoplasm
A
- thick fluid within the cell membrane
- structures and organelles are suspended in it
- cytosol: liquid part of the cytoplasm (75-90% water)
2
Q
what is a Golgi body
A
- flattened membranes stacked on top of one another
- modify and package proteins in vesicles for secretion
3
Q
what is the mitochondria
A
- spherical structures
- double membrane (outer; smooth, inner; folded in towards the centre)
- release energy for the cell through the process of respiration
4
Q
what is centrioles
A
- pair of cylindrical structures
- involved in the reproduction / mitosis of the cell
5
Q
what is the nucleus
A
- contains the genetic material (DNA)
- nuclear membrane: separates nucleus from cytoplasm
- nuclear pores: gaps in the membrane
- nucleolus: contains RNA, plays part in manufacture of proteins
6
Q
what are ribosomes
A
- amino acids join to them to make proteins
- can be attached to membranes within the cell or free in cytoplasm
7
Q
what is the cytoskeleton
A
- consists of microfilaments and microtubules
- give cell its shape and assist the movement of materials, organelles or the whole
8
Q
what are lysosomes
A
- contain enzymes able to break down proteins, lipids, nucleic acids, carbohydrates
- break down materials taken into the cell
- breakdown worn-out organelles
9
Q
what is the endoplasmic reticulum
A
- pairs of parallel membranes
- connect cell membrane to the nuclear membrane
- provides a surface area for chemical reactions to occur
- channels between membranes are used for storage and transport of materials
- rough e.r: ribosomes
- smooth e.r: no ribosomes
10
Q
what are inclusions
A
- substances that are not part of the cell structure but are found in the cytoplasm
11
Q
what is the cell membrane
A
- outer boundary of cell separating the internal and external environment
- made up of a double lipid bilayer (phosphate heads and lipid tails)
- semi-permeable membrane
- determines what enters and leaves the cell
