Cell Structure and Division Flashcards
What do animal cells lack that plant cells have?
Cell wall, vacuole and chloroplast
Eukaryotic cells have ________ organelles
membrane-bound
Do plant cells have both a cell wall and membrane? What are they made of?
Yes
Cell wall made from cellulose
Cell surface membrane of phospholipids
Algal/fungal cells lack _____, which other plant cells have. Why?
Lack chloroplasts
They don’t photosynthesise
Function of the cell surface membrane?
- Regulates the movement of substances into and out of the cell.
- It also has receptor molecules on it, which allow it to respond to chemicals like hormones.
Describe the structure of a nucleus x3
Surrounded by an nuclear envelope (double membrane), which contains pores. Contains chromosomes (which are made from protein-bound linear DNA) and one or more structures called a nucleolus.
Functions of the nucleus x2
- Controls the cell’s activities (by controlling the transcription of DNA).
- The nucleolus makes ribosomes.
Describe the structure of a mitochondria x4
- Oval Shaped;
- double membrane;
– the inner membrane is folded to form structures called cristae; - inside is the mitochondrial matrix
Function of mitochondrion? x1
Site of aerobic respiration, where ATP is produced.
Describe the structure of a chloroplast x4
- Surrounded by a double membrane;
- also has membranes inside called thylakoid membranes. - These are stacked up in some parts of the chloroplast to form grana.
- Grana are linked together by lamellae – thin, flat pieces of thylakoid membrane.
Chloroplasts are found in which types of cells?
In plant and algal cells
Function of chloroplasts? x1
- Site of photosynthesis takes place. (Some parts of photosynthesis happen in the grana and others in the stroma (a thick liquid found in chloroplasts)).
Describe the structure of the Golgi apparatus
A group of fluid-filled, membrane bound, flattened sacs. Vesicles are often seen on the edges of the sacs.
Functions of Golgi apparatus? x2
Modifies and packages new lipids and proteins.
It also makes lysosomes.
Functions of Golgi vesicles? x2
Store lipids and proteins made by apparatus and transports them out of the cell (exocytosis)
Describe the structure of a lysosome
- Round organelle
- surrounded by a membrane,
- no clear internal structure
Function of a lysosome?
- Contains digestive enzymes called lysozymes. Used to digest invading cells or to break down worn out components of the cell.
What types of molecule are ribosomes made of?
Made of proteins and ribosomal RNA.
Function of a ribosome?
- Site of protein synthesis and translation. Proteins are made here.
Two parts of ribosome?
Small sub-unit and large sub-unit
Ribosomes are membrane bound organelles. True/false?
False. Ribosomes are not membrane bound organelles.
Where are ribosomes found?
Either floating freely in the cytoplasm or attached to the rough endoplasmic reticulum
Describe the structure of the Rough Endoplasmic Reticulum x2
A system of membranes enclosing a fluid-filled space.
The surface is covered in ribosomes.
Describe the functions of the Rough Endoplasmic Reticulum x2
Makes and transports proteins
Describe the functions of the Smooth Endoplasmic Reticulum x2
Synthesises and processes lipids
Describe the structure of the Smooth Endoplasmic Reticulum x2
Similar to rough endoplasmic reticulum except there is no ribosomes
Function of cell wall?
Supports cells and prevents them from changing shape
What is the cell wall made of? x2
In plants and algae it’s made mainly made of cellulose.
In fungi its made of a chitin.