Unit 1 Flashcards
What is the cell membranes function?
Selective permeable layer which controls which substances can enter and exit the cell
Where is the site of chemical reaction?
Cytoplasm
What is the function of mitochondria?
Location where respiration occurs and most of the cells ATP is produced
What is the function of ribosomes
Location where amino acids are connected together to produce proteins
What are proteins made out of?
Amino acids
What is the function of the nucleus?
Stores DNA and therefore controls activities of the cell
What are the cell walls in plants made out of?
Cellulose
What is a cell wall?
freely permeable layer surrounding cell membrane that’s made of cellulose.
What is the function of the cell wall?
Supports and strengths cell
What is the function of chloroplasts?
Location where photosynthesis occurs and sugar is produced
What’s the function of the vacuole?
Water storage
What type of cells have a cell wall that is NOT made up of cellulose?
Fungal cell and bacteria cell
What does a plant cell consist of?
Nucleus, chloroplasts, vacuole, cell wall, cell membrane, mitochondria, ribosomes
What does an animal cell consist of?
Cytoplasm, cell membrane, ribosomes, nucleus
What does a fungal cell consist of?
Ribosomes, mitochondria, nucleus, cell membrane, cell wall
What cell is like an animal cell but has a cell wall?
Fungal cell
What does a bacterial cell consist of?
Cell wall, cell membrane, cytoplasm, ribosomes, plasmids, large circular DNA molecule
What cell has a no nucleus ?
Bacterial cell
Where does a bacterial cells DNA float ?
In the cytoplasm
How many layers are in the cell membrane?
2
What are the layers in a cell membrane made out of ?
Phospholipids and proteins
Is the cell membrane selectively permeable?
Yes
What does selectively permeable mean ?
it means that it lets Some substances through and prevents others from passing through at all
What type of transport doesn’t need energy?
Passive
What type of transport needs energy?
Active
What is the equation for percentage change?
New value - old value
——————————- X 100%
Old value
When does active transport occur?
When molecules are moved across the cell membrane from an area where they are at a low concentration to an area of high concentration by specific membrane proteins
Why does active transport require energy?
Because the movement is against the concentration gradient
What is diffusion?
Movements of molecules from a high concentration to a low concentration
What is osmosis?
The diffusion of water to a high concentration to a low concentration through a selectively permeable membrane
What happens in a plant cell where the concentration is the same?
Equal water concentration, no osmosis occurs
What happens in a plant cell with a high water concentration?
Cell swells and becomes turgid
What happens in a plant cell with a low water concentration?
Cell membrane peels away from cell wall and is plasmolysed
What happens in an animal cell with the same concentration?
Stays the same
What happens in an animal cell with a high water concentration?
Water moves in the cell and it bursts
What happens in a animal cell with a low water concentration?
Water moves out and cell shrinks
What is the shape of DNA?
double helix
How are the 2 strands of DNA held together?
By weak bonds between pairs of bases
What are the letters of the bases in DNA ?
A T C G
What does A pair with ?
T
What does C pair with ?
G
What are chromosomes ?
Thread-like structures found in the nucleus and made of tightly coiled DNA
What are the 4 DNA bases called (full names)
Adenine , thymine , cytosine , guanine
What do proteins consist of ?
Long chains of repeating chemicals called amino acids
What is the word given to the group of 3 bases that represent different amino acids
Triplets
What is a gene ?
A sequence of bases of DNA that codes for a protein
Where is mRNA made ?
The nucleus
What does mRNA do ?
Carries a copy of a gene to the cytoplasm
What about mRNA makes it easier to leave the nucleus?
It is single stranded
What order does mRNA go in ?
Carries a complementary copy of the genetic code from the DNA, in the nucleus, to a ribosome, where protein is assembled, from amino acids
Roughly , how many different amino acids are there ?
About 20
How are the order of amino acids determined?
By the sequence of the base pairs in the gene
What do enzymes do ?
Catalyse biological reactions
What is the function of hormones?
Communication between different parts of the body.
How are hormones released?
From endocrine glands and are transported in the blood to target cells
What is the function of antibodies?
Part of the immune system. They are produced by white blood cells and can bind to specific bacteria and viruses
What is the function of structural amino acids?
Forms supporting framework inside cells and forms structures e.g. collagen
What are the function receptors?
Specific proteins found on cell membranes
What are enzymes?
Enzymes are biological catalysts, this means they speed up reactions, but do not get used up in the reaction
What are enzymes made from ?
They are made from protein, which means they are building blocks of amino acids
How do amino acids join together?
In a long chain, which folds to make a unique 3D shape
What is the chemical called that enzymes act on?
Substrates
What are the substances called that enzymes produce?
Products
Why is the shape of an enzyme important?
Because it affects the type of reaction
What is an active site ?
The part of an enzyme to Whitchurch one or more substrate molecules can attach
Why are enzymes specific?
Because different enzymes have different shaped active sites
What is a degradation reaction?
When enzymes speed up the brake down of complex molecules into simpler molecules
Give examples of degradation reactions
Catalase speeding up the break down of hydrogen peroxide (HPCOW) or amylase speeding up the breakdown of starch into maltose
What does hydrogen peroxide break down into with catalase?
Water + oxygen
What are synthesis reactions
When enzymes catalase by joining together 2 substrates to form a product
What is the dependant variable ?
The thing that is being measured
What is the independent variable?
The thing you are changing
