Final answer:
The kidney filtrate contains everything blood plasma has except for proteins(option 1), which are too large to pass through the glomerular filtration barrier.
Step-by-step explanation:
The student asked which large molecules are not found in kidney filtrate that are present in blood plasma. The correct option is 1) Proteins. In the kidneys, the glomeruli filter the blood based mostly on particle size. Large molecules such as blood cells, platelets, antibodies, and albumen (proteins) are excluded from the filtrate.
Smaller molecules like glucose, water, salts, ions, and amino acids are filtered into the filtrate and may be reabsorbed later in the nephron. The process is critical for maintaining homeostasis by balancing the concentrations of these substances in the body and excreting excesses.
In some conditions, such as diabetes, if there is more glucose than the carrier proteins can handle, the excess glucose will not be reabsorbed and will be excreted in the urine, which is referred to as 'spilling glucose into the urine'. Unlike glucose, proteins are generally too large to pass through the filtration barrier under normal conditions.