Flashcards in Cells Deck (58)
What is the third step of mitosis?
-nucleus membrane breakdown
- the chromosomes line up on equator of the cell
Why is the first step of mitosis?
DNA is tightly coiled in the nucleus
Explain the function of receptor enzymes
Cell identity tags
Describe the structure of the cell membrane?
Phospholipids make up the basic structure
And it's made up of protein and lipids(fat)
Name two facts about DNA?
- double stranded
- twisted into a double helix
Name the three parts of a nucleotide ?
Phosphate, deoxyribose sugar and base
What is DNA structure made up of?
Name two parts of a chromosome?
Describe function of a cell wall?
Maintains cell shape/support
Describe function of chloroplasts?
Site of photosynthesis
Describe stage 5 of mitosis
- chromatids are pulled to opposite ends of the cell
-nuclear membranes formed
- two identical daughter cells are formed
Higher water concentration outside plant cell?(3 marks)
Higher water concentration outside cell, water moves into cell, cell=turgid
Same water concentration outside plant cell?
Water movement Is balanced
What is the second step of mitosis?
-chromosomes shorten and thicken
-chromosomes double to form two identical chromatids which join at a centromere
Lower water concentration outside plant cell?(3marks)
Higher water concentration in cell, water moves out cell, cell is plasmolysed
Higher water concentration outside animal cell?(2 marks)
Higher water concentration outside cell, water moves into cell, cells burgs
Explain"optimum" in terms of enzymes
Conditions enzymes work best at, usually body temp
State an enzyme equation
Hydrogen peroxide ---------->oxygen and water
Explain function of an antibody enzyme
Describe function of a hormone protein
Body messenger eg insulin
Explain function of enzyme protein
Speed up chemical reactions eg amylase
Explain how proteins have different shapes
They all have different jobs to do
Describe how DNA is carried to the ribosomes
By a messenger molecule called MRNA
Name the base pairs
What does active transport require?
Describe process of active transport
The moment of molecules from a low concentration to a high concentration against a concentration gradient
What's the simple enzyme equation?
Co2 and water --------------> oxygen and glucose
Three things plants use glucose for
Respiration, stored as starch, makes cellulose