Cells & DNA do tonight Flashcards
2.1.1 euk cells, 2.1.3 Microscopes, 4.2 protein synthesis, 4.3/8.1 mutations and gene DNA replication, 4.3 Meosis, 4.1 prok cells, 1.5.2 semi conservative replication, 2.2 cell cycle, mitosis, 2.1.2prok vs euk, 2.2 Binary fission
Nucleus
Chromosomes contain DNA which controls the synthesis of proteins. Ribosomes are formed in the nucleolus
Nucleus structure
large organelle enclosed by a double membrane (envelope) perforated by pores. Contains chromosomes and one or more nucleoli.
5 parts of nucleus
Nuclear pores - allows passage of large molecules
Nuclear envelope - entry and exit - surrounded by ribosomes
Nucleoplasm
Chromosomes - protein bound DNA
Nucleolous- manufactures rRNA and assembles ribosomes - in nucleoplasm
Ribosomes
very small organelle not bound by a membrane. Consists of a large and a small subunit. Made of protein and RNA.
Ribosomes function
uses the information in nucleic acid to synthesis proteins.
Protein synthesis
Vesicle
contains digestive enzymes
small membrane bound sphere
transport large molecules for exocytosis or to add membrane to different organelles
vesicle function
Responsible for destroying worn out organelles and for digesting the content of vacuoles formed by phagocytosis.
Centrioles structure
A pair of short cylinders. Each cylinder is made up of nine fibres.
Centrioles function
form a spindle- shaped structure of protein fibres on which the chromosomes move during nuclear division.
Vacuole structure
a sac bound by a single membrane. Contains cell sap which is a solution of mineral salts, pigments, organic acids and other substances.
Vacuole function
stores waste products and other substances. Changes in volume affect the turgidity of the cell.
Function of a vacuole
1- support herbaceous plants - turgidity
2- Sugar and AA act as a temporary food store.
3- Pigment - many colour petals - attract pollinating insects
cell membrane
a phospholipid bilayer with intrinsic and extrinsic protein molecules.
cell membrane function
a partially permeable carrier which controls the passage of substances into and out of the cell
- controls diffusion of molecules and ions between cytoplasm and surrounding fluid.
Rough endoplasmic reticulin
Forms a system of channels for transporting materials through the cytoplasm. One type has ribosomes on its surface and is the site of protein synthesis. The other type has no ribosomes and is where steroids and other lipids are synthesised.
Rough endoplasmic reticulin function
a complex network of flattened membrane- bound sacs called cisternae. Often has ribosomes on the cytoplasmic side.
Ribosomes made from…
RNa/ rRNA, Proteins
DNA vs mRNA
- deoxyribose vs ribose
- thymine vs uracil
- long vs short
- double stranded vs single stranded
- Hydrogen bonds vs no HB
- Complementary base pairing vs no
why is the Resolution in Electron microscopes higher?
shorter wavelength between electrons
longer wavelength In light rays
Describe how to determine size and structure with microscope of an organisms
1- measure and divide by magnification
2- Micrometers to cm x10000
or
1- measure and divide by length of scale bar
2- Multiply by actual length of scale bar