Unit 2 Topic 3 Flashcards
What is the function of the cell surface membrane in prokaryotes
- As bacteria does not contain mitochondria, the cell membrane is the site of some respiratory enzymes
What are mesosomes
- Infoldings in the cell membrane of some bacteria
- Involved with enzyme activity or photosynthesis
What are capsules for prokaryotes
- A slime layer around the cell wall
- Made of starch, gelatin, protein or glycolipids
- Protects bacteria from phagocytosis
What are pili
- Projections in some bacteria
- Used in attatchment to the host cell or in sexual reproduction
What is the flagella
- Made of flagellin protein
- Allows bacteria to move by rapid rotations
What is a nucleoid
- The area in which the genetic material is found
- Genetic material is a single chromosome, made up of circular coiled DNA molecule
What are plasmids
- Small circles of DNA, found in some bacteria
- They code for a particular aspect in the bacterial phemotyple
- They replicate themselves independent of the nucleoid
- Can be transferred from one bacterium to another through pili in sexual reproduction
What is 70s ribosomes involved in
Protein synthesis
What is the bacterial cell wall
- Formed of peptidoglycan
- Prevents swelling and bursting of the cell as the bacteria contents are hypertonic to their medium
Describe the structure of the mitochondria
- They are surrounded by an outer and an inner membrane
- The inner membrane is folded into cristae surrounded by a fluid matrix
- Contain mitochodrial DNA that helps replicate the mitochondria during cell division under the control of the nucleus
- They contain 70S ribosomes
What are centrioles
- There are 2 centrioles near the nucleus
- Each centriole is made up of 9 grouples of tubules, each is composed of 3 tubules
- They are involved in cell division where wach centriole produces spindle fibres involved in the movement of the chromosomes
What is the cytoskeleton
- Web-like structure tht fills the cytoplasm
- Made up of microfilaments and microtubules
- Gives the cytoplasm structure and keeps the organelles in place
- They help cell movement and transport within the cell
What are lysosomes
- Spherical bodies in the cytoplasm, they contain digestive enzymes
- They fuse to a membrane bound organelle containing food or an obsolete organelle
- The enzymes break down the contents into materials that can be reused
What are the 2 types of endoplasmic reticulum
- Rough endoplasmic reticulum
- Smooth endoplasmic reticulum
Describe the process that occurs in the rER
- ER is covered from outside by ribosomes which make proteins
- rER folds and transports these proteins once they have formed
- The large surface area of ER helps synthesis, storing and transporting proteins within and outside the cell
Describe the processin sER
- Involved in the synthesis and transport of steroids and lipids as testostoron ahd cholestorol
Describe the properties of the Golgi apparatus
- Made of stack or parallel, flattened membrane pockets
- Formed by vesicles from ER fused together
Describe the function of the Golgi apparatus
- Proteins are brought to the Golgi apparatus in vesicles which have been pinched off the ER
- proteins then enter Gogli body stacks to be modified
- Carbohydrates added to protein to form glycoprotein as mucus
- Proteins as digestive enzymes are packed in vesicles to form lysosomes that move to the cell surface membrane, fuse to it and release their contents outside the cell
Define tissues
Groups of specialised cells carrying out particular functions in the body
Define organs
Structures made of several different types of tissue to carry out particular functions in the body
