Key Concepts In Biology Flashcards
The ribosomes are the site of
Protein synthesis
All cells need energy to function. Which cell organelle is responsible for releasing energy in the cell through aerobic respiration
Mitochondria
What is the function of vacuoles
Storing water
Why do very active cells have lots of mitochondria
As mitochondria release energy
Which cell structure is found in plant and animals cells and controls what can come into or leave a cell?
Cell membrane
What is the function of a cell wall
To protect and support the cell
What is the function of a nucleus
To control cell activity
What does the mitochondria do
This is where aerobic respiration occur
What happens in the cytoplasm
A jelly like liquid where chemical reactions take place
What do the chloroplasts do
They contain chlorophyll to absorb sunlight where photosynthesis occurs
Prokaryotic
A single called organism with no nucleus
Eukaryotic
An organism with have a nucleus
Enzymes?
A biological catalyst that increases the rate of a reaction being chemically unchanged. By lowering the activation energy
What is synthesis
This is when a New product is formed
3 things that increase the rate of diffusion
The greater the difference in particle concentration
The greater the kinetic energy
The greater the temperature
What do carbohydrates break down into
Simple sugars
What enzyme breaks down carbohydrates
Amylase/ carbohydrase
What do we call the model that explains enzyme specificity?
The lock and key model
What is the optimum temperature for enzymes
37.5 degrees c
What is the optimum pH for enzymes (except pepsin!)
Between 6-8 most optimum at 7
What is the optimum ph for pepsin
Between 2-3
What does protease break down
Protein
How is the enzyme substrate complex formed
When substrate binds to the enzyme
What happens on the active site of an enzyme
This is where the substrate binds
How can the shape of an enzyme make it inactive
Small or blocked active site making it imposible for the substrate to fit perfectly making it impossible to form the enzyme substrate complex
What are enzymes made of
Each enzyme is comprised of proteins made of these twisting and folding amino acids,
How does temperature denature an enzyme
Extreme temperature breaks the forces between the amino acids that hold together a cell changing its shape
How does ph denature an enzyme
Changing the pH will affect the charges on the amino acid molecules. Amino acids that attracted each other may no longer be. This changing the shape of the active site
Describe how sperm cells are adapted to their function.
Acrosomes, which help to identify the target female reproductive cell and contain enzymes that break down the outer membrane of the egg, allowing the sperm to achieve fertilisation.
Describe how ciliated epithelial cells are adapted to their function.
They have have cilia (which are hair-like structures) on the top surface of the cell. These cells move substances in one direction. These can be found along the lining of the airways. They move mucus.
How are egg cells adapted
The cytoplasm contains a large volume of nutrients to help the embryo grow.
They are lined with cilia that helps move substances away.
They have a protective jelly coat that hardens after fertilization.
The egg cell membrane can fuse with the sperm cell membrane.
The effect of substrate concentration on an enzyme
the rate of enzyme activity does not increase forever. This is because a point will be reached when the enzymes become saturated and no more substrates can fit at any one time
Active transport
Active transport is the movement of dissolved molecules into or out of a cell through the cell membrane, from a region of lower concentration to a region of higher concentration. The particles move against the concentration gradient , using energy released during respiration .
Effects of osmosis on a red blood cell
Red blood cells placed in a solution with a higher water concentration compared to their contents (eg pure water) will gain water by osmosis, swell up and burst. Water will diffuse from a higher water concentration outside the cell to a lower water concentration inside the cell.
