Chapter 2- Structure and Function of Cells Flashcards
What is the cell wall and what is its function?
The cell wall and is made of cellulose in plant cells and chitin in bacterial cells. It is thick, rigid membrane which surrounds the cell and provides it with support and structure.
What is the plasma membrane and what does it do?
The plasma membrane surrounds the cell and is made of a partially permeable phospholipid bi-layer. It regulates the movement of substances in and out of the cell.
What is the nucleus and what is its function?
The nucleus contains the genetic information and instructions for the cell in eukaryotic cells. It is surrounded by a nuclear envelope.
What are the mitochondria and what are their function?
The mitochondria are primarily responsible for metabolism sugar molecules into usable ATP. It is the main energy source for the majority of cellular functions. Each mitochondrion has many folds to allow respiration to occur faster.
What are ribosomes and what are their function?
Ribosomes are not a real organelle due their presence in prokaryotic cells and their lack of a membrane. They are found on the rough ER or free in the cytoplasm. They are made up of ribosomal RNA. They make proteins by linking amino acids together.
What is a vesicle and what is its function?
Vesicles are part of the membrane that bud of and transport substances in an out of the cell as well as within it.
What is the endoplasmic reticulum and what does it do?
The ER transports substances within the cell, it is continuous withy the nuclear membrane. There are two types of ER:
Rough ER- responsible for the synthesis, folding and modification of proteins. It can be recognised by the ribosomes contained on it.
Smooth ER- responsible for the synthesis of lipids (fats- such as oils, phospholipids and steroids). It is also responsible for the detoxification of drugs and poisons.
What is the Golgi apparatus and what does it do?
The Golgi is made of stacks of membrane bound disks that is responsible for modification, packaging and secretion of proteins and lipids out of the cell. It can be recognised by the vesicles budding off it.
What are lysosomes and what are their function?
A single membrane-bound sac of hydrolytic enzymes. They are responsible for intracellular digestion of macro molecules and the recycling of cellular components.
What are chloroplasts and what are their function?
Chloroplasts are double membrane-bound organelles that are only found in plant cells. They are made up of grena (chlorophyll containing plastids) and stroma (solution). They are responsible for carrying out photosynthesis.
What is the vacuole and what is it responsible for?
The vacuole is a membrane-bound sac that is filled with fluid and dissolved substances. It is responsible for maintaining optimum pressure and support for the cell. They are usually larger in plant cells.
What are the flagella and cilia and what do they do?
The flagella and cilia are found in prokaryotic cells. They provide cell mobility (flagella) or, in cells held in place, the movement of fluid over the cell (cilia).
What is the cytoplasm and what does it do?
The cytoplasm is the watery medium of a cell where chemical reactions take place and the cell’s organelles are found.
What features distinguish plant cells?
Presence of a cell wall, chloroplasts and large vacuole. Absence of lysosomes.
What are the four processes that allow the movement of substances in and out of the cell?
- diffusion
- osmosis
- active transport
- bulk transport
