A1.2.1-A2.3.6 Flashcards
To learn everything there is to know about part A
List the four main macromolecules ( optional)
1.lipids
2.protein
3.Carbohydrates
4.Nucleic acids
What are nucleic acids ?
A macromolecule found inside the living systems and they makeup important structures such as DNA
What does DNA stand for
Deoxyribonucleic acid
What is DNA
A long molecule consisting of repeating subunits called nucleotides that carries genetic material
Explain nucleotides
Building blocks of nucleic acids . It consists of a pentose sugar molecule called ribose , phosphate group (PO4-3) and a nitrogen base
Draw a simple version of a nucleotide and label it
Look in the textbook I can’t add pictures apparently
What is the backbone of DNA and RNA ?
Sugar -phosphate molecules
Write the nitrogenous bases of DNA
Cytosine, guanine, adenine , thymine
Draw the two strands of a DNA
In ur notebook
Write the differences between DNA and RNA
- DNA has two strands but RNA has one
- DNA has thymine but RNA has Uracil
- DNA lacks an oxygen but RNA has two
How do the nucleotides in an RNA connect to each other?
Using a condensation reaction where water is formed from the bond between sugar and phosphate molecules
Complementary base pairing
Adenine with thymine using hydrogen bonds and Cytosine and guanine
Where are nucleic acids found ( just for better understanding)
The cell’s nucleus
What are purines and what are pyrimidines ?
Adenine and Guanine—> purines ( 2 rings)
Cytosine and thymine—> pyrimidines
5’ is for— and 3’ is for—
Phosphate
Sugar
Nucleosome
Consists of 8 proteins called histones and then the DNA wraps around it almost twice and an H1 protein strengthens the whole thing
What is the pattern of abundance between A , G , C and T ?
Adenine and thymine are almost alike and Guanine and Cytosine are almost alike
What’s the importance of 5’ , 3’ ?
A nucleotide can only attach to a 3’ end and so if we don’t have a 3’ end there won’t be a stable structure.
Describe Replication
It has a 5’ to 3’ direction . Both strands of DNA are used. One moves in the same direction of the strand but the other one moves on the opposite direction
Transcription
5’ to 3’ . One strand of DNA is used to a RNA . It moves in the same direction
What are the 3 requirements for a cell
- Ability to use energy to function
- Be able to self sustain meaning that they can support themselves
3.can pass genetic material to offspring
What are the developments required for the origin of cells
Catalysis- giving control over which reactions occur
Self-assembly- how they assemble
Compartmentalisation- it must have a membrane
Self-replication— obvious
Name some advantages of RNA for being the first genetic material
- Self replicates
- Can act as a catalyst ( natural enzyme)
- Mutates at a higher rate
Approaches to finding estimate dates of LUCA
- Carbon dating
- Fossils
- Using genetical differences
Name and explain the common structures between all cells
- Plasma membrane- the membrane
- Cytoplasm
- DNA
What are some qualities of prokaryotes
1.70S ribosomes ( helps make proteins)
2. Lack a nucleus
3. Non-compartmentalised
4. No histones
5. Bacteria’s mostly
Eukaryotes characters
- Nucleus - double membrane and contains dna ( associates with histone proteins )
- 80S ribosomes
- Mitochondria
Nucleus
¥ double nuclear membrane
¥ pores
¥ contains chromosomes/ DNA / histones
¥ DNA is replicated and transcribed to form mRNA
Name exceptions in cell structures
Blood cells , pholem sieve tube elements, skeletal muscle
Rough endoplasmic reticulum ( rER)
¥Consists of flattened membrane sacs called cisternae
¥ 80S ribosomes are attached to the outside of these Cisternae
¥ main function is to synthesise ( make) proteins using the help of ribosomes which are then sent to cisternaes and carried by vesicles to the Golgi apparatus
Golgi apparatus
¥ contains flattened sacs called cisternae . Are shorter and more curved.
Do not have attached ribosomes but many vesicles nearby
¥ purpose is to process proteins and then carry them to plasma membrane for secretion using vesicles
Lysosomes
¥ spherical with a single membrane. Formed from Golgi apparatuses. Contains high concentrations of protein
¥ contain digestive enzymes to break down food , organelles and cells
SmoothER
¥ consists of branched networks of tubular membranes . They look like circles or ovals
¥ the membrane is smooth because there are no ribosomes attached
¥ it’s function is to synthesise lipids, phospholipids and steroids
Mitochondria
¥ double membrane, inner membrane is folded in itself creating cristae . A fluid inside it is called matrix 💊❤️💊💙. It usually looks ovoid or spherical
¥ helps with fat digestion and produce ATP for the cell using aerobic respiration
Free ribosomes
Not surrounded by a membrane. Synthesises proteins and releases it . They are formed in the nucleolus ( a region of the nucleus)
Common features of viruses
- Very small
- Can’t grow ( fixed size )
3.have genetic material ( either DNA or RNA ) - Contain Capsid lytic cyout of protein enclosing genetic material)
- No cytoplasm or enzyme ( or very few )
Lytic cycle
- Attachement to the host via the tail of the virus
- DNA enters host’s cell
- DNA replicates itself
- mRNA
is formed which are then translated to make viral proteins - Proteins are synthesised using the ribosome of the cell
6&7. The poke holes into the cells and spread out to infect other cells
Lysogenic cycle
- Attachement
- DNA enters the cell
- The DNA attaches itself to the host’s cell’s DNA .
- Cell division which helps other cells also get infected because the DNA is infected
