Cells Flashcards
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?
Nucleotides
Name two parts of a chromosome?
Chromatids, centromere
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
HP COW
Hydrogen peroxide ———->oxygen and water
Catalase
Explain function of an antibody enzyme
Fight infections
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
A+T G+C
What does active transport require?
Energy
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?
Substrates———->product
Enzymes
Photosynthesis equation?
Sunlight
Co2 and water ————–> oxygen and glucose
Chlorophyll
Three things plants use glucose for
Respiration, stored as starch, makes cellulose
Three limiting factors of photosynthesis
Light intensity, carbon dioxide, temperature
Where does photosynthesis happen?
In the chlorplasts
ATP is made from what?
ADP + PI
What is step one of aerobic respiration?
Glycolysis
What’s step two of aerobic respiration?
Citric acid cycle
Where does glycolysis is take place?
Cyptoplasm
Where does citric acid cycle take place?
Mitochondria
Step one of aerobic respiration(3 marks)
Happens in Cyptoplasm, glucose splits onto two pyruvic acid molecules, produces two ATP
Step two of aerobic respiration (3 marks)
Happens in mitochondria, pyruvic acid is broken down, produces CO2, water and 36 ATP
What does aerobic respiration have that anaerobic doesn’t ?
Owygen
Aerobic respiration equation
Glucose and oxygen—-> 36ATP, CO2 and water
Equation for anaerobic respiration in plants and fungi
Glucose—> 2 ATP, CO2 and ethanol
Equation for anaerobic respiration in animal and bacteria cells
Glucose—> 2ATP and lactic acid
Describe function of mitochondria
Site of aerobic respiration
Describe the process of osmosis
Movement of water from high conc water to a low conc water down a conc gradient through a selectively permeable membrane
Lower water conc outside animal cell
Higher water conc in cell, water moves out cell, cell shrinks
Describe the process of diffusion and give examples
Movement of substances from an area of high concentration to an area of low through conc gradient
What does body use energy for?
Muscle cell contraction, cell division , protein synthesis
Stage 4 of mitosis
Spindle fibers attach each centromere to the pole. The spindle fibers shorten and pull the chromatids apart
Describe function of a structural protein
Forms hair and nails eg keratin
Explain term “specific” in terms of enzymes
Each enzyme can only catalyze one reaction
Describe function of ribosome
Site of protein synthesis
Describe function of vacuole
Stores water and solutes
Describe function of cell membrane
Controls movements of substance in and out of cell
Explain importance of mitosis
New cells must have an exact copy of DNA so no,info is lost
State what mitosis is
Process of cell division
Explain denatured in terms of enzymes
Heated above certain temperatures their shape begins to change. Can no longer bond with their substrates
Describe function of nucleus
Controls cells activity
Describe functions of cyptoplasm
Jelly like filling, site of chemical reactions